Re: [racket-users] a little bug
On Fri, Feb 28, 2020 at 07:11:02AM -0600, Robby Findler wrote: > Oh, sorry-- I misunderstood. > > In v7.5, there will be, in some cases, a source location after you > dismiss that dialog. In the pre-release builds, that's been improved > somewhat and source location information is more reliably available. Excellent. > That said, there are limitations and it isn't always available. Of course. If the entire process gets shut down because of memory overrun there isn't much left to report on. > > Thanks for using DrR! It's the easiest way to use Racket. -- hendrik > > Robby > > On Fri, Feb 28, 2020 at 6:31 AM Hendrik Boom wrote: > > > > On Fri, Feb 28, 2020 at 06:02:31AM -0600, Robby Findler wrote: > > > I agree that would be great. In the meantime, the Run button does a better > > > job with error reporting in various ways, including this one so hopefully > > > you can try that? > > > > That's what I was using. There was a popup message that wasn't any more > > informative. > > It says: > > > > - The evaluation thread is no longer running, so > > no evaluation can take place until the next > > execution. > > > > The program ran out of memory. > > [V]Show thid dialog ext time > > [Increase memory limit to 256 megabytes][OK] > > > > I'm mentioning this to indicate a way the drracket uer-interface can be > > improved, especially for beginners. > > > > I'm not asking Racket maintainers to step in and debug my code. > > > > (Further analysis (by deleting code until there was almost nothing left) > > indicates it crashed during processing the #lang line at the start. > > I have started private correspondence with the language author.) > > > > -- hendrik > > > > > > Robby > > > > > > On Fri, Feb 28, 2020 at 5:45 AM Hendrik Boom > > > wrote: > > > > > > > > > > > When Racket detects the out-of-memory condition during "background > > > > processing", it would be useful i the out-of-memory message were to > > > > point > > > > out which particular piece of source text it was having trouble with. > > > > Just > > > > the line number where the expression started that the REPL was having > > > > trouble with would be a huge help. > > > > > > > > And by the way, if Dr. Racket were to be a she, she would be addressed > > > > in > > > > Quebec as Dre. Racket. > > > > > > > > On Friday, 5 February 2016 19:19:46 UTC-5, jon stenerson wrote: > > > > > > > >> lol. Don't be sorry. Speaking of anthropomorphization, I really love > > > >> Dr > > > >> Racket and hope I didn't hurt his feelings (Or is Dr Racket a she?). I > > > >> employ his services whenever I can. I don't mean to be a whiner; he > > > >> deserves better than that! > > > >> > > > >> Jon > > > >> > > > >> On 2/5/2016 3:44 PM, Robby Findler wrote: > > > >> > Sorry we can't do better. And it is really amazing how I actually > > > >> > think so anthropomorphically about these things. :) That really was a > > > >> > literal brain dump. > > > >> > > > > >> > Robby > > > >> > > > > >> > On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson > > > >> wrote: > > > >> >> Thanks for the explanation. I appreciate it. > > > >> >> > > > >> >> > > > >> >> On 2/5/2016 1:55 PM, Robby Findler wrote: > > > >> >>> In general, DrRacket does not promise to avoid this situation. Let > > > >> >>> me > > > >> >>> explain a little bit. This program is effectively equivalent to > > > >> >>> this > > > >> >>> one: > > > >> >>> > > > >> >>> #lang racket/base > > > >> >>> (define (run l) > > > >> >>> (run (cons 'x l))) > > > >> >>> (run '()) > > > >> >>> > > > >> >>> (but running at compile time, which is why things happen > > > >> >>> automatically, but lets leave that aside for now). > > > >> >>> > > > >> >>> So when you run that program, DrRacket is asking the operating > > > >> >>> system > > > >> >>> for all of its memory. At some point, the operating system says > > > >> >>> "sorry, no, we're out of memory" and since the program running > > > >> >>> inside > > > >> >>> DrRacket doesn't really care that we're out of memory, the > > > >> >>> operating > > > >> >>> system responds with "die!". And so DrRacket dies. > > > >> >>> > > > >> >>> There are two ways we try to do better. First: we can set limits on > > > >> >>> the memory. But if the limit is set to be higher than the amount of > > > >> >>> memory available on the machine, then it is as if the memory limit > > > >> >>> isn't set. Also worth noting at this point: the way that DrRacket's > > > >> >>> counting of "how much memory" is only loosely related to the way > > > >> >>> that > > > >> >>> your machine's vendor or the OS counts. There are some constant > > > >> >>> factors of difference there that depend on things like how the > > > >> garbage > > > >> >>> collector is configured and how many other programs are running on > > > >> >>> your system and what they are doing (like the OS itself likes to > > > >> >>> have > > > >> >>> some of the memory and it (quite reasonably) doesn't want to s
Re: [racket-users] a little bug
Oh, sorry-- I misunderstood. In v7.5, there will be, in some cases, a source location after you dismiss that dialog. In the pre-release builds, that's been improved somewhat and source location information is more reliably available. That said, there are limitations and it isn't always available. Thanks for using DrR! Robby On Fri, Feb 28, 2020 at 6:31 AM Hendrik Boom wrote: > > On Fri, Feb 28, 2020 at 06:02:31AM -0600, Robby Findler wrote: > > I agree that would be great. In the meantime, the Run button does a better > > job with error reporting in various ways, including this one so hopefully > > you can try that? > > That's what I was using. There was a popup message that wasn't any more > informative. > It says: > > - The evaluation thread is no longer running, so > no evaluation can take place until the next > execution. > > The program ran out of memory. > [V]Show thid dialog ext time > [Increase memory limit to 256 megabytes][OK] > > I'm mentioning this to indicate a way the drracket uer-interface can be > improved, especially for beginners. > > I'm not asking Racket maintainers to step in and debug my code. > > (Further analysis (by deleting code until there was almost nothing left) > indicates it crashed during processing the #lang line at the start. > I have started private correspondence with the language author.) > > -- hendrik > > > > Robby > > > > On Fri, Feb 28, 2020 at 5:45 AM Hendrik Boom wrote: > > > > > > > > When Racket detects the out-of-memory condition during "background > > > processing", it would be useful i the out-of-memory message were to point > > > out which particular piece of source text it was having trouble with. > > > Just > > > the line number where the expression started that the REPL was having > > > trouble with would be a huge help. > > > > > > And by the way, if Dr. Racket were to be a she, she would be addressed in > > > Quebec as Dre. Racket. > > > > > > On Friday, 5 February 2016 19:19:46 UTC-5, jon stenerson wrote: > > > > > >> lol. Don't be sorry. Speaking of anthropomorphization, I really love Dr > > >> Racket and hope I didn't hurt his feelings (Or is Dr Racket a she?). I > > >> employ his services whenever I can. I don't mean to be a whiner; he > > >> deserves better than that! > > >> > > >> Jon > > >> > > >> On 2/5/2016 3:44 PM, Robby Findler wrote: > > >> > Sorry we can't do better. And it is really amazing how I actually > > >> > think so anthropomorphically about these things. :) That really was a > > >> > literal brain dump. > > >> > > > >> > Robby > > >> > > > >> > On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson > > >> wrote: > > >> >> Thanks for the explanation. I appreciate it. > > >> >> > > >> >> > > >> >> On 2/5/2016 1:55 PM, Robby Findler wrote: > > >> >>> In general, DrRacket does not promise to avoid this situation. Let me > > >> >>> explain a little bit. This program is effectively equivalent to this > > >> >>> one: > > >> >>> > > >> >>> #lang racket/base > > >> >>> (define (run l) > > >> >>> (run (cons 'x l))) > > >> >>> (run '()) > > >> >>> > > >> >>> (but running at compile time, which is why things happen > > >> >>> automatically, but lets leave that aside for now). > > >> >>> > > >> >>> So when you run that program, DrRacket is asking the operating system > > >> >>> for all of its memory. At some point, the operating system says > > >> >>> "sorry, no, we're out of memory" and since the program running inside > > >> >>> DrRacket doesn't really care that we're out of memory, the operating > > >> >>> system responds with "die!". And so DrRacket dies. > > >> >>> > > >> >>> There are two ways we try to do better. First: we can set limits on > > >> >>> the memory. But if the limit is set to be higher than the amount of > > >> >>> memory available on the machine, then it is as if the memory limit > > >> >>> isn't set. Also worth noting at this point: the way that DrRacket's > > >> >>> counting of "how much memory" is only loosely related to the way that > > >> >>> your machine's vendor or the OS counts. There are some constant > > >> >>> factors of difference there that depend on things like how the > > >> garbage > > >> >>> collector is configured and how many other programs are running on > > >> >>> your system and what they are doing (like the OS itself likes to have > > >> >>> some of the memory and it (quite reasonably) doesn't want to share > > >> >>> that memory). > > >> >>> > > >> >>> The second way is that the OS will sometimes say "you are about to > > >> >>> cause me to exhaust all of the system's memory and if you do that, I > > >> >>> will kill you" at which point the GC inside Racket responds with > > >> >>> "okay, I'll just die first". The main advantage of this is that you > > >> >>> get an error message saying "out of memory" from Racket instead of an > > >> >>> error message saying "I killed your program" from the OS (which is > > >> the > > >> >>> message you're getting). It turns out to be remarkab
Re: [racket-users] a little bug
On Fri, Feb 28, 2020 at 06:02:31AM -0600, Robby Findler wrote: > I agree that would be great. In the meantime, the Run button does a better > job with error reporting in various ways, including this one so hopefully > you can try that? That's what I was using. There was a popup message that wasn't any more informative. It says: - The evaluation thread is no longer running, so no evaluation can take place until the next execution. The program ran out of memory. [V]Show thid dialog ext time [Increase memory limit to 256 megabytes][OK] I'm mentioning this to indicate a way the drracket uer-interface can be improved, especially for beginners. I'm not asking Racket maintainers to step in and debug my code. (Further analysis (by deleting code until there was almost nothing left) indicates it crashed during processing the #lang line at the start. I have started private correspondence with the language author.) -- hendrik > > Robby > > On Fri, Feb 28, 2020 at 5:45 AM Hendrik Boom wrote: > > > > > When Racket detects the out-of-memory condition during "background > > processing", it would be useful i the out-of-memory message were to point > > out which particular piece of source text it was having trouble with. Just > > the line number where the expression started that the REPL was having > > trouble with would be a huge help. > > > > And by the way, if Dr. Racket were to be a she, she would be addressed in > > Quebec as Dre. Racket. > > > > On Friday, 5 February 2016 19:19:46 UTC-5, jon stenerson wrote: > > > >> lol. Don't be sorry. Speaking of anthropomorphization, I really love Dr > >> Racket and hope I didn't hurt his feelings (Or is Dr Racket a she?). I > >> employ his services whenever I can. I don't mean to be a whiner; he > >> deserves better than that! > >> > >> Jon > >> > >> On 2/5/2016 3:44 PM, Robby Findler wrote: > >> > Sorry we can't do better. And it is really amazing how I actually > >> > think so anthropomorphically about these things. :) That really was a > >> > literal brain dump. > >> > > >> > Robby > >> > > >> > On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson > >> wrote: > >> >> Thanks for the explanation. I appreciate it. > >> >> > >> >> > >> >> On 2/5/2016 1:55 PM, Robby Findler wrote: > >> >>> In general, DrRacket does not promise to avoid this situation. Let me > >> >>> explain a little bit. This program is effectively equivalent to this > >> >>> one: > >> >>> > >> >>> #lang racket/base > >> >>> (define (run l) > >> >>> (run (cons 'x l))) > >> >>> (run '()) > >> >>> > >> >>> (but running at compile time, which is why things happen > >> >>> automatically, but lets leave that aside for now). > >> >>> > >> >>> So when you run that program, DrRacket is asking the operating system > >> >>> for all of its memory. At some point, the operating system says > >> >>> "sorry, no, we're out of memory" and since the program running inside > >> >>> DrRacket doesn't really care that we're out of memory, the operating > >> >>> system responds with "die!". And so DrRacket dies. > >> >>> > >> >>> There are two ways we try to do better. First: we can set limits on > >> >>> the memory. But if the limit is set to be higher than the amount of > >> >>> memory available on the machine, then it is as if the memory limit > >> >>> isn't set. Also worth noting at this point: the way that DrRacket's > >> >>> counting of "how much memory" is only loosely related to the way that > >> >>> your machine's vendor or the OS counts. There are some constant > >> >>> factors of difference there that depend on things like how the > >> garbage > >> >>> collector is configured and how many other programs are running on > >> >>> your system and what they are doing (like the OS itself likes to have > >> >>> some of the memory and it (quite reasonably) doesn't want to share > >> >>> that memory). > >> >>> > >> >>> The second way is that the OS will sometimes say "you are about to > >> >>> cause me to exhaust all of the system's memory and if you do that, I > >> >>> will kill you" at which point the GC inside Racket responds with > >> >>> "okay, I'll just die first". The main advantage of this is that you > >> >>> get an error message saying "out of memory" from Racket instead of an > >> >>> error message saying "I killed your program" from the OS (which is > >> the > >> >>> message you're getting). It turns out to be remarkably difficult to > >> >>> get this error message to work in all situations. We're better than > >> we > >> >>> used to be at it, but at some level, the best we can do in that case > >> >>> is really just to change the text of the error message. When we're > >> out > >> >>> of memory like that, it's very very hard to recover if the limits are > >> >>> not set up ahead of time (i.e. back to the previous paragraph). > >> >>> > >> >>> I hope this clears up the issue somewhat. > >> >>> > >> >>> In the meantime, I suggest you lower the memory limit for your > >> machine. > >> >>> > >>
Re: [racket-users] a little bug
I agree that would be great. In the meantime, the Run button does a better job with error reporting in various ways, including this one so hopefully you can try that? Robby On Fri, Feb 28, 2020 at 5:45 AM Hendrik Boom wrote: > > When Racket detects the out-of-memory condition during "background > processing", it would be useful i the out-of-memory message were to point > out which particular piece of source text it was having trouble with. Just > the line number where the expression started that the REPL was having > trouble with would be a huge help. > > And by the way, if Dr. Racket were to be a she, she would be addressed in > Quebec as Dre. Racket. > > On Friday, 5 February 2016 19:19:46 UTC-5, jon stenerson wrote: > >> lol. Don't be sorry. Speaking of anthropomorphization, I really love Dr >> Racket and hope I didn't hurt his feelings (Or is Dr Racket a she?). I >> employ his services whenever I can. I don't mean to be a whiner; he >> deserves better than that! >> >> Jon >> >> On 2/5/2016 3:44 PM, Robby Findler wrote: >> > Sorry we can't do better. And it is really amazing how I actually >> > think so anthropomorphically about these things. :) That really was a >> > literal brain dump. >> > >> > Robby >> > >> > On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson >> wrote: >> >> Thanks for the explanation. I appreciate it. >> >> >> >> >> >> On 2/5/2016 1:55 PM, Robby Findler wrote: >> >>> In general, DrRacket does not promise to avoid this situation. Let me >> >>> explain a little bit. This program is effectively equivalent to this >> >>> one: >> >>> >> >>> #lang racket/base >> >>> (define (run l) >> >>> (run (cons 'x l))) >> >>> (run '()) >> >>> >> >>> (but running at compile time, which is why things happen >> >>> automatically, but lets leave that aside for now). >> >>> >> >>> So when you run that program, DrRacket is asking the operating system >> >>> for all of its memory. At some point, the operating system says >> >>> "sorry, no, we're out of memory" and since the program running inside >> >>> DrRacket doesn't really care that we're out of memory, the operating >> >>> system responds with "die!". And so DrRacket dies. >> >>> >> >>> There are two ways we try to do better. First: we can set limits on >> >>> the memory. But if the limit is set to be higher than the amount of >> >>> memory available on the machine, then it is as if the memory limit >> >>> isn't set. Also worth noting at this point: the way that DrRacket's >> >>> counting of "how much memory" is only loosely related to the way that >> >>> your machine's vendor or the OS counts. There are some constant >> >>> factors of difference there that depend on things like how the >> garbage >> >>> collector is configured and how many other programs are running on >> >>> your system and what they are doing (like the OS itself likes to have >> >>> some of the memory and it (quite reasonably) doesn't want to share >> >>> that memory). >> >>> >> >>> The second way is that the OS will sometimes say "you are about to >> >>> cause me to exhaust all of the system's memory and if you do that, I >> >>> will kill you" at which point the GC inside Racket responds with >> >>> "okay, I'll just die first". The main advantage of this is that you >> >>> get an error message saying "out of memory" from Racket instead of an >> >>> error message saying "I killed your program" from the OS (which is >> the >> >>> message you're getting). It turns out to be remarkably difficult to >> >>> get this error message to work in all situations. We're better than >> we >> >>> used to be at it, but at some level, the best we can do in that case >> >>> is really just to change the text of the error message. When we're >> out >> >>> of memory like that, it's very very hard to recover if the limits are >> >>> not set up ahead of time (i.e. back to the previous paragraph). >> >>> >> >>> I hope this clears up the issue somewhat. >> >>> >> >>> In the meantime, I suggest you lower the memory limit for your >> machine. >> >>> >> >>> Robby >> >>> >> >>> >> >>> >> > >>> On Fri, Feb 5, 2016 at 10:53 AM, jon stenerson >> >> > >>> wrote: >> Actually you don't even have to run the program. With memory limit >> set to >> 1024, just open a file containing the expression and wait. After a >> minute >> or >> two DrRacket puts up a MSVC runtime error dialog. >> >> >> On 2/5/2016 9:39 AM, jon stenerson wrote: >> > Setting the limit lower helped. Thanks. I did not see that message >> about >> > Background Expansion Terminated before. Now I do. >> > >> > Jon >> > >> > On 2/5/2016 6:55 AM, Robby Findler wrote: >> >> It took a while for mine for the custodian limit to be reached and >> for >> >> the expansion to run out of memory. It may be that the threshhold >> for >> >> the memory use is too high on some systems. Maybe the right thing >> is >> >> to set the default a bit lower? >> >> >> >> Jon: if you open th
Re: [racket-users] a little bug
When Racket detects the out-of-memory condition during "background processing", it would be useful i the out-of-memory message were to point out which particular piece of source text it was having trouble with. Just the line number where the expression started that the REPL was having trouble with would be a huge help. And by the way, if Dr. Racket were to be a she, she would be addressed in Quebec as Dre. Racket. On Friday, 5 February 2016 19:19:46 UTC-5, jon stenerson wrote: > > lol. Don't be sorry. Speaking of anthropomorphization, I really love Dr > Racket and hope I didn't hurt his feelings (Or is Dr Racket a she?). I > employ his services whenever I can. I don't mean to be a whiner; he > deserves better than that! > > Jon > > On 2/5/2016 3:44 PM, Robby Findler wrote: > > Sorry we can't do better. And it is really amazing how I actually > > think so anthropomorphically about these things. :) That really was a > > literal brain dump. > > > > Robby > > > > On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson > wrote: > >> Thanks for the explanation. I appreciate it. > >> > >> > >> On 2/5/2016 1:55 PM, Robby Findler wrote: > >>> In general, DrRacket does not promise to avoid this situation. Let me > >>> explain a little bit. This program is effectively equivalent to this > >>> one: > >>> > >>> #lang racket/base > >>> (define (run l) > >>> (run (cons 'x l))) > >>> (run '()) > >>> > >>> (but running at compile time, which is why things happen > >>> automatically, but lets leave that aside for now). > >>> > >>> So when you run that program, DrRacket is asking the operating system > >>> for all of its memory. At some point, the operating system says > >>> "sorry, no, we're out of memory" and since the program running inside > >>> DrRacket doesn't really care that we're out of memory, the operating > >>> system responds with "die!". And so DrRacket dies. > >>> > >>> There are two ways we try to do better. First: we can set limits on > >>> the memory. But if the limit is set to be higher than the amount of > >>> memory available on the machine, then it is as if the memory limit > >>> isn't set. Also worth noting at this point: the way that DrRacket's > >>> counting of "how much memory" is only loosely related to the way that > >>> your machine's vendor or the OS counts. There are some constant > >>> factors of difference there that depend on things like how the garbage > >>> collector is configured and how many other programs are running on > >>> your system and what they are doing (like the OS itself likes to have > >>> some of the memory and it (quite reasonably) doesn't want to share > >>> that memory). > >>> > >>> The second way is that the OS will sometimes say "you are about to > >>> cause me to exhaust all of the system's memory and if you do that, I > >>> will kill you" at which point the GC inside Racket responds with > >>> "okay, I'll just die first". The main advantage of this is that you > >>> get an error message saying "out of memory" from Racket instead of an > >>> error message saying "I killed your program" from the OS (which is the > >>> message you're getting). It turns out to be remarkably difficult to > >>> get this error message to work in all situations. We're better than we > >>> used to be at it, but at some level, the best we can do in that case > >>> is really just to change the text of the error message. When we're out > >>> of memory like that, it's very very hard to recover if the limits are > >>> not set up ahead of time (i.e. back to the previous paragraph). > >>> > >>> I hope this clears up the issue somewhat. > >>> > >>> In the meantime, I suggest you lower the memory limit for your > machine. > >>> > >>> Robby > >>> > >>> > >>> > >>> On Fri, Feb 5, 2016 at 10:53 AM, jon stenerson > > >>> wrote: > Actually you don't even have to run the program. With memory limit > set to > 1024, just open a file containing the expression and wait. After a > minute > or > two DrRacket puts up a MSVC runtime error dialog. > > > On 2/5/2016 9:39 AM, jon stenerson wrote: > > Setting the limit lower helped. Thanks. I did not see that message > about > > Background Expansion Terminated before. Now I do. > > > > Jon > > > > On 2/5/2016 6:55 AM, Robby Findler wrote: > >> It took a while for mine for the custodian limit to be reached and > for > >> the expansion to run out of memory. It may be that the threshhold > for > >> the memory use is too high on some systems. Maybe the right thing > is > >> to set the default a bit lower? > >> > >> Jon: if you open the "Racket" menu you should see a "Limit > Memory..." > >> menu item. How does DrRacket do if you change the number in there > to > >> 256 and then paste the program into the definitions window? Do you > see > >> the red message at the bottom of t
Re: [racket-users] a little bug
lol. Don't be sorry. Speaking of anthropomorphization, I really love Dr Racket and hope I didn't hurt his feelings (Or is Dr Racket a she?). I employ his services whenever I can. I don't mean to be a whiner; he deserves better than that! Jon On 2/5/2016 3:44 PM, Robby Findler wrote: Sorry we can't do better. And it is really amazing how I actually think so anthropomorphically about these things. :) That really was a literal brain dump. Robby On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson wrote: Thanks for the explanation. I appreciate it. On 2/5/2016 1:55 PM, Robby Findler wrote: In general, DrRacket does not promise to avoid this situation. Let me explain a little bit. This program is effectively equivalent to this one: #lang racket/base (define (run l) (run (cons 'x l))) (run '()) (but running at compile time, which is why things happen automatically, but lets leave that aside for now). So when you run that program, DrRacket is asking the operating system for all of its memory. At some point, the operating system says "sorry, no, we're out of memory" and since the program running inside DrRacket doesn't really care that we're out of memory, the operating system responds with "die!". And so DrRacket dies. There are two ways we try to do better. First: we can set limits on the memory. But if the limit is set to be higher than the amount of memory available on the machine, then it is as if the memory limit isn't set. Also worth noting at this point: the way that DrRacket's counting of "how much memory" is only loosely related to the way that your machine's vendor or the OS counts. There are some constant factors of difference there that depend on things like how the garbage collector is configured and how many other programs are running on your system and what they are doing (like the OS itself likes to have some of the memory and it (quite reasonably) doesn't want to share that memory). The second way is that the OS will sometimes say "you are about to cause me to exhaust all of the system's memory and if you do that, I will kill you" at which point the GC inside Racket responds with "okay, I'll just die first". The main advantage of this is that you get an error message saying "out of memory" from Racket instead of an error message saying "I killed your program" from the OS (which is the message you're getting). It turns out to be remarkably difficult to get this error message to work in all situations. We're better than we used to be at it, but at some level, the best we can do in that case is really just to change the text of the error message. When we're out of memory like that, it's very very hard to recover if the limits are not set up ahead of time (i.e. back to the previous paragraph). I hope this clears up the issue somewhat. In the meantime, I suggest you lower the memory limit for your machine. Robby On Fri, Feb 5, 2016 at 10:53 AM, jon stenerson wrote: Actually you don't even have to run the program. With memory limit set to 1024, just open a file containing the expression and wait. After a minute or two DrRacket puts up a MSVC runtime error dialog. On 2/5/2016 9:39 AM, jon stenerson wrote: Setting the limit lower helped. Thanks. I did not see that message about Background Expansion Terminated before. Now I do. Jon On 2/5/2016 6:55 AM, Robby Findler wrote: It took a while for mine for the custodian limit to be reached and for the expansion to run out of memory. It may be that the threshhold for the memory use is too high on some systems. Maybe the right thing is to set the default a bit lower? Jon: if you open the "Racket" menu you should see a "Limit Memory..." menu item. How does DrRacket do if you change the number in there to 256 and then paste the program into the definitions window? Do you see the red message at the bottom of the screen or does DrRacket still run out of memory? Anthony: I don' thave a good solution for you, but I find that the menu key short cut (control-k for you?) for killing is more likely to get thru, because it requires a lot less event handling than the others. Robby On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi wrote: On my system it behaves almost exactly as described by Jon (6.3, windows). The one difference is that DrRacket hasn't crashed yet, but the Task manager reports one processor at 100% and memory use slowly growing. Currently is at 7.5 GB. On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: On 02/05/2016 08:01 AM, Robby Findler wrote: When I run this, I see a message at the bottom of the DrRacket window (in red): Background expansion terminated abnormally (out of memory) do you see this message? I tried too, and it stops fine with the same message as Robby. No phantom CPU usage apparent. However, I did have a run away DrRacket recently that didn't respond to stop and took a few minutes to kill because my UI was extremely sluggish (partially because X11 and/or the window manager sucks,
Re: [racket-users] a little bug
Sorry we can't do better. And it is really amazing how I actually think so anthropomorphically about these things. :) That really was a literal brain dump. Robby On Fri, Feb 5, 2016 at 3:53 PM, jon stenerson wrote: > Thanks for the explanation. I appreciate it. > > > On 2/5/2016 1:55 PM, Robby Findler wrote: >> >> In general, DrRacket does not promise to avoid this situation. Let me >> explain a little bit. This program is effectively equivalent to this >> one: >> >> #lang racket/base >> (define (run l) >>(run (cons 'x l))) >> (run '()) >> >> (but running at compile time, which is why things happen >> automatically, but lets leave that aside for now). >> >> So when you run that program, DrRacket is asking the operating system >> for all of its memory. At some point, the operating system says >> "sorry, no, we're out of memory" and since the program running inside >> DrRacket doesn't really care that we're out of memory, the operating >> system responds with "die!". And so DrRacket dies. >> >> There are two ways we try to do better. First: we can set limits on >> the memory. But if the limit is set to be higher than the amount of >> memory available on the machine, then it is as if the memory limit >> isn't set. Also worth noting at this point: the way that DrRacket's >> counting of "how much memory" is only loosely related to the way that >> your machine's vendor or the OS counts. There are some constant >> factors of difference there that depend on things like how the garbage >> collector is configured and how many other programs are running on >> your system and what they are doing (like the OS itself likes to have >> some of the memory and it (quite reasonably) doesn't want to share >> that memory). >> >> The second way is that the OS will sometimes say "you are about to >> cause me to exhaust all of the system's memory and if you do that, I >> will kill you" at which point the GC inside Racket responds with >> "okay, I'll just die first". The main advantage of this is that you >> get an error message saying "out of memory" from Racket instead of an >> error message saying "I killed your program" from the OS (which is the >> message you're getting). It turns out to be remarkably difficult to >> get this error message to work in all situations. We're better than we >> used to be at it, but at some level, the best we can do in that case >> is really just to change the text of the error message. When we're out >> of memory like that, it's very very hard to recover if the limits are >> not set up ahead of time (i.e. back to the previous paragraph). >> >> I hope this clears up the issue somewhat. >> >> In the meantime, I suggest you lower the memory limit for your machine. >> >> Robby >> >> >> >> On Fri, Feb 5, 2016 at 10:53 AM, jon stenerson >> wrote: >>> >>> Actually you don't even have to run the program. With memory limit set to >>> 1024, just open a file containing the expression and wait. After a minute >>> or >>> two DrRacket puts up a MSVC runtime error dialog. >>> >>> >>> On 2/5/2016 9:39 AM, jon stenerson wrote: Setting the limit lower helped. Thanks. I did not see that message about Background Expansion Terminated before. Now I do. Jon On 2/5/2016 6:55 AM, Robby Findler wrote: > > It took a while for mine for the custodian limit to be reached and for > the expansion to run out of memory. It may be that the threshhold for > the memory use is too high on some systems. Maybe the right thing is > to set the default a bit lower? > > Jon: if you open the "Racket" menu you should see a "Limit Memory..." > menu item. How does DrRacket do if you change the number in there to > 256 and then paste the program into the definitions window? Do you see > the red message at the bottom of the screen or does DrRacket still run > out of memory? > > Anthony: I don' thave a good solution for you, but I find that the > menu key short cut (control-k for you?) for killing is more likely to > get thru, because it requires a lot less event handling than the > others. > > Robby > > > On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi > > wrote: >> >> On my system it behaves almost exactly as described by Jon (6.3, >> windows). >> >> The one difference is that DrRacket hasn't crashed yet, but the Task >> manager reports one processor at 100% and memory use slowly growing. >> Currently is at 7.5 GB. >> >> >> >> >> >> On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico >> >> wrote: >>> >>> On 02/05/2016 08:01 AM, Robby Findler wrote: When I run this, I see a message at the bottom of the DrRacket window (in red): Background expansion terminated abnormally (out of memory) do you see this message? >>> >>> I tried too, and it stops fine with the same
Re: [racket-users] a little bug
Thanks for the explanation. I appreciate it. On 2/5/2016 1:55 PM, Robby Findler wrote: In general, DrRacket does not promise to avoid this situation. Let me explain a little bit. This program is effectively equivalent to this one: #lang racket/base (define (run l) (run (cons 'x l))) (run '()) (but running at compile time, which is why things happen automatically, but lets leave that aside for now). So when you run that program, DrRacket is asking the operating system for all of its memory. At some point, the operating system says "sorry, no, we're out of memory" and since the program running inside DrRacket doesn't really care that we're out of memory, the operating system responds with "die!". And so DrRacket dies. There are two ways we try to do better. First: we can set limits on the memory. But if the limit is set to be higher than the amount of memory available on the machine, then it is as if the memory limit isn't set. Also worth noting at this point: the way that DrRacket's counting of "how much memory" is only loosely related to the way that your machine's vendor or the OS counts. There are some constant factors of difference there that depend on things like how the garbage collector is configured and how many other programs are running on your system and what they are doing (like the OS itself likes to have some of the memory and it (quite reasonably) doesn't want to share that memory). The second way is that the OS will sometimes say "you are about to cause me to exhaust all of the system's memory and if you do that, I will kill you" at which point the GC inside Racket responds with "okay, I'll just die first". The main advantage of this is that you get an error message saying "out of memory" from Racket instead of an error message saying "I killed your program" from the OS (which is the message you're getting). It turns out to be remarkably difficult to get this error message to work in all situations. We're better than we used to be at it, but at some level, the best we can do in that case is really just to change the text of the error message. When we're out of memory like that, it's very very hard to recover if the limits are not set up ahead of time (i.e. back to the previous paragraph). I hope this clears up the issue somewhat. In the meantime, I suggest you lower the memory limit for your machine. Robby On Fri, Feb 5, 2016 at 10:53 AM, jon stenerson wrote: Actually you don't even have to run the program. With memory limit set to 1024, just open a file containing the expression and wait. After a minute or two DrRacket puts up a MSVC runtime error dialog. On 2/5/2016 9:39 AM, jon stenerson wrote: Setting the limit lower helped. Thanks. I did not see that message about Background Expansion Terminated before. Now I do. Jon On 2/5/2016 6:55 AM, Robby Findler wrote: It took a while for mine for the custodian limit to be reached and for the expansion to run out of memory. It may be that the threshhold for the memory use is too high on some systems. Maybe the right thing is to set the default a bit lower? Jon: if you open the "Racket" menu you should see a "Limit Memory..." menu item. How does DrRacket do if you change the number in there to 256 and then paste the program into the definitions window? Do you see the red message at the bottom of the screen or does DrRacket still run out of memory? Anthony: I don' thave a good solution for you, but I find that the menu key short cut (control-k for you?) for killing is more likely to get thru, because it requires a lot less event handling than the others. Robby On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi wrote: On my system it behaves almost exactly as described by Jon (6.3, windows). The one difference is that DrRacket hasn't crashed yet, but the Task manager reports one processor at 100% and memory use slowly growing. Currently is at 7.5 GB. On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: On 02/05/2016 08:01 AM, Robby Findler wrote: When I run this, I see a message at the bottom of the DrRacket window (in red): Background expansion terminated abnormally (out of memory) do you see this message? I tried too, and it stops fine with the same message as Robby. No phantom CPU usage apparent. However, I did have a run away DrRacket recently that didn't respond to stop and took a few minutes to kill because my UI was extremely sluggish (partially because X11 and/or the window manager sucks, and my CPU probably throttled, but still...). I don't have any good data for you about the circumstances of the issue though. -- Anthony Carrico -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Ra
Re: [racket-users] a little bug
In general, DrRacket does not promise to avoid this situation. Let me explain a little bit. This program is effectively equivalent to this one: #lang racket/base (define (run l) (run (cons 'x l))) (run '()) (but running at compile time, which is why things happen automatically, but lets leave that aside for now). So when you run that program, DrRacket is asking the operating system for all of its memory. At some point, the operating system says "sorry, no, we're out of memory" and since the program running inside DrRacket doesn't really care that we're out of memory, the operating system responds with "die!". And so DrRacket dies. There are two ways we try to do better. First: we can set limits on the memory. But if the limit is set to be higher than the amount of memory available on the machine, then it is as if the memory limit isn't set. Also worth noting at this point: the way that DrRacket's counting of "how much memory" is only loosely related to the way that your machine's vendor or the OS counts. There are some constant factors of difference there that depend on things like how the garbage collector is configured and how many other programs are running on your system and what they are doing (like the OS itself likes to have some of the memory and it (quite reasonably) doesn't want to share that memory). The second way is that the OS will sometimes say "you are about to cause me to exhaust all of the system's memory and if you do that, I will kill you" at which point the GC inside Racket responds with "okay, I'll just die first". The main advantage of this is that you get an error message saying "out of memory" from Racket instead of an error message saying "I killed your program" from the OS (which is the message you're getting). It turns out to be remarkably difficult to get this error message to work in all situations. We're better than we used to be at it, but at some level, the best we can do in that case is really just to change the text of the error message. When we're out of memory like that, it's very very hard to recover if the limits are not set up ahead of time (i.e. back to the previous paragraph). I hope this clears up the issue somewhat. In the meantime, I suggest you lower the memory limit for your machine. Robby On Fri, Feb 5, 2016 at 10:53 AM, jon stenerson wrote: > Actually you don't even have to run the program. With memory limit set to > 1024, just open a file containing the expression and wait. After a minute or > two DrRacket puts up a MSVC runtime error dialog. > > > On 2/5/2016 9:39 AM, jon stenerson wrote: >> >> Setting the limit lower helped. Thanks. I did not see that message about >> Background Expansion Terminated before. Now I do. >> >> Jon >> >> On 2/5/2016 6:55 AM, Robby Findler wrote: >>> >>> It took a while for mine for the custodian limit to be reached and for >>> the expansion to run out of memory. It may be that the threshhold for >>> the memory use is too high on some systems. Maybe the right thing is >>> to set the default a bit lower? >>> >>> Jon: if you open the "Racket" menu you should see a "Limit Memory..." >>> menu item. How does DrRacket do if you change the number in there to >>> 256 and then paste the program into the definitions window? Do you see >>> the red message at the bottom of the screen or does DrRacket still run >>> out of memory? >>> >>> Anthony: I don' thave a good solution for you, but I find that the >>> menu key short cut (control-k for you?) for killing is more likely to >>> get thru, because it requires a lot less event handling than the >>> others. >>> >>> Robby >>> >>> >>> On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi >>> wrote: On my system it behaves almost exactly as described by Jon (6.3, windows). The one difference is that DrRacket hasn't crashed yet, but the Task manager reports one processor at 100% and memory use slowly growing. Currently is at 7.5 GB. On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: > > On 02/05/2016 08:01 AM, Robby Findler wrote: >> >> When I run this, I see a message at the bottom of the DrRacket window >> (in red): >> >>Background expansion terminated abnormally (out of memory) >> >> do you see this message? > > I tried too, and it stops fine with the same message as Robby. No > phantom CPU usage apparent. > > However, I did have a run away DrRacket recently that didn't respond to > stop and took a few minutes to kill because my UI was extremely > sluggish > (partially because X11 and/or the window manager sucks, and my CPU > probably throttled, but still...). I don't have any good data for you > about the circumstances of the issue though. > > -- > Anthony Carrico > > -- > You received this message because you are subscribed to the Google > Groups "Racket Users" group. > To unsubscribe from this g
Re: [racket-users] a little bug
Actually you don't even have to run the program. With memory limit set to 1024, just open a file containing the expression and wait. After a minute or two DrRacket puts up a MSVC runtime error dialog. On 2/5/2016 9:39 AM, jon stenerson wrote: Setting the limit lower helped. Thanks. I did not see that message about Background Expansion Terminated before. Now I do. Jon On 2/5/2016 6:55 AM, Robby Findler wrote: It took a while for mine for the custodian limit to be reached and for the expansion to run out of memory. It may be that the threshhold for the memory use is too high on some systems. Maybe the right thing is to set the default a bit lower? Jon: if you open the "Racket" menu you should see a "Limit Memory..." menu item. How does DrRacket do if you change the number in there to 256 and then paste the program into the definitions window? Do you see the red message at the bottom of the screen or does DrRacket still run out of memory? Anthony: I don' thave a good solution for you, but I find that the menu key short cut (control-k for you?) for killing is more likely to get thru, because it requires a lot less event handling than the others. Robby On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi wrote: On my system it behaves almost exactly as described by Jon (6.3, windows). The one difference is that DrRacket hasn't crashed yet, but the Task manager reports one processor at 100% and memory use slowly growing. Currently is at 7.5 GB. On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: On 02/05/2016 08:01 AM, Robby Findler wrote: When I run this, I see a message at the bottom of the DrRacket window (in red): Background expansion terminated abnormally (out of memory) do you see this message? I tried too, and it stops fine with the same message as Robby. No phantom CPU usage apparent. However, I did have a run away DrRacket recently that didn't respond to stop and took a few minutes to kill because my UI was extremely sluggish (partially because X11 and/or the window manager sucks, and my CPU probably throttled, but still...). I don't have any good data for you about the circumstances of the issue though. -- Anthony Carrico -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] a little bug
Setting the limit lower helped. Thanks. I did not see that message about Background Expansion Terminated before. Now I do. Jon On 2/5/2016 6:55 AM, Robby Findler wrote: It took a while for mine for the custodian limit to be reached and for the expansion to run out of memory. It may be that the threshhold for the memory use is too high on some systems. Maybe the right thing is to set the default a bit lower? Jon: if you open the "Racket" menu you should see a "Limit Memory..." menu item. How does DrRacket do if you change the number in there to 256 and then paste the program into the definitions window? Do you see the red message at the bottom of the screen or does DrRacket still run out of memory? Anthony: I don' thave a good solution for you, but I find that the menu key short cut (control-k for you?) for killing is more likely to get thru, because it requires a lot less event handling than the others. Robby On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi wrote: On my system it behaves almost exactly as described by Jon (6.3, windows). The one difference is that DrRacket hasn't crashed yet, but the Task manager reports one processor at 100% and memory use slowly growing. Currently is at 7.5 GB. On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: On 02/05/2016 08:01 AM, Robby Findler wrote: When I run this, I see a message at the bottom of the DrRacket window (in red): Background expansion terminated abnormally (out of memory) do you see this message? I tried too, and it stops fine with the same message as Robby. No phantom CPU usage apparent. However, I did have a run away DrRacket recently that didn't respond to stop and took a few minutes to kill because my UI was extremely sluggish (partially because X11 and/or the window manager sucks, and my CPU probably throttled, but still...). I don't have any good data for you about the circumstances of the issue though. -- Anthony Carrico -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] a little bug
It took a while for mine for the custodian limit to be reached and for the expansion to run out of memory. It may be that the threshhold for the memory use is too high on some systems. Maybe the right thing is to set the default a bit lower? Jon: if you open the "Racket" menu you should see a "Limit Memory..." menu item. How does DrRacket do if you change the number in there to 256 and then paste the program into the definitions window? Do you see the red message at the bottom of the screen or does DrRacket still run out of memory? Anthony: I don' thave a good solution for you, but I find that the menu key short cut (control-k for you?) for killing is more likely to get thru, because it requires a lot less event handling than the others. Robby On Fri, Feb 5, 2016 at 7:41 AM, Pierpaolo Bernardi wrote: > On my system it behaves almost exactly as described by Jon (6.3, windows). > > The one difference is that DrRacket hasn't crashed yet, but the Task > manager reports one processor at 100% and memory use slowly growing. > Currently is at 7.5 GB. > > > > > > On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: >> On 02/05/2016 08:01 AM, Robby Findler wrote: >>> When I run this, I see a message at the bottom of the DrRacket window (in >>> red): >>> >>> Background expansion terminated abnormally (out of memory) >>> >>> do you see this message? >> >> I tried too, and it stops fine with the same message as Robby. No >> phantom CPU usage apparent. >> >> However, I did have a run away DrRacket recently that didn't respond to >> stop and took a few minutes to kill because my UI was extremely sluggish >> (partially because X11 and/or the window manager sucks, and my CPU >> probably throttled, but still...). I don't have any good data for you >> about the circumstances of the issue though. >> >> -- >> Anthony Carrico >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Racket Users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to racket-users+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] a little bug
On my system it behaves almost exactly as described by Jon (6.3, windows). The one difference is that DrRacket hasn't crashed yet, but the Task manager reports one processor at 100% and memory use slowly growing. Currently is at 7.5 GB. On Fri, Feb 5, 2016 at 2:29 PM, Anthony Carrico wrote: > On 02/05/2016 08:01 AM, Robby Findler wrote: >> When I run this, I see a message at the bottom of the DrRacket window (in >> red): >> >> Background expansion terminated abnormally (out of memory) >> >> do you see this message? > > I tried too, and it stops fine with the same message as Robby. No > phantom CPU usage apparent. > > However, I did have a run away DrRacket recently that didn't respond to > stop and took a few minutes to kill because my UI was extremely sluggish > (partially because X11 and/or the window manager sucks, and my CPU > probably throttled, but still...). I don't have any good data for you > about the circumstances of the issue though. > > -- > Anthony Carrico > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] a little bug
On 02/05/2016 08:01 AM, Robby Findler wrote: > When I run this, I see a message at the bottom of the DrRacket window (in > red): > > Background expansion terminated abnormally (out of memory) > > do you see this message? I tried too, and it stops fine with the same message as Robby. No phantom CPU usage apparent. However, I did have a run away DrRacket recently that didn't respond to stop and took a few minutes to kill because my UI was extremely sluggish (partially because X11 and/or the window manager sucks, and my CPU probably throttled, but still...). I don't have any good data for you about the circumstances of the issue though. -- Anthony Carrico -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] a little bug
When I run this, I see a message at the bottom of the DrRacket window (in red): Background expansion terminated abnormally (out of memory) do you see this message? Robby On Thu, Feb 4, 2016 at 10:29 PM, jon stenerson wrote: > > #lang racket > (let ((x 1)) > (letrec-syntax ((m (lambda (t) (syntax (m) > (m))) > > When I run this in DrRacket 6.3 on Win 10 it starts looping. I hit the stop > button. The interaction window says "user break" and is ready for another > command. > > However, the windows task manager shows DrRacket being very active and > eating more and more memory. After a minute DrRacket crashes. I guess the > bug is that the stop button doesn't stop the expander? > > Jon > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] a little bug
#lang racket (let ((x 1)) (letrec-syntax ((m (lambda (t) (syntax (m) (m))) When I run this in DrRacket 6.3 on Win 10 it starts looping. I hit the stop button. The interaction window says "user break" and is ready for another command. However, the windows task manager shows DrRacket being very active and eating more and more memory. After a minute DrRacket crashes. I guess the bug is that the stop button doesn't stop the expander? Jon -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
