[racket-users] error with no location and no traceback, with -l errotrace etc. - how do you get racket to say where?

Ok, here is a new one, but first a summary. To summarize, I originally posted a number of racket error messages that had no backtrace, or no backtrace nor location information. So far, here is people have contributed as fixes, though unfortunately cases remain (see below): 1. errortrace is in

[racket-users] current-text-keymap-initializer problems in v6.2.1

I've been messing around with GUI programming and I came across current-text-keymap-initializer which, according to the documentation, may accept a procedure that itself takes a single parameter (a keymap%). Now, I've tried to invoke this via `(current-text-keymap-initializer (lambda (keymap)

[racket-users] "bad variable linkage" after restarting handin server under load

Hi all, it's me, handin server guy again. Sorry to bother. Our handin server started "crashing" with "bad variable linkage" errors at deadline time (presumably under somewhat high load), and since it happened twice, I thought I'd report it. Any ideas on what's causing this? After this "crash",

Re: [racket-users] current-text-keymap-initializer problems in v6.2.1

I'm not able to replicate that problem, but I'm unclear on where `init-editor-keymap` comes from. Is that something in your code? The function for the `current-text-keymap-initializer` parameter really should accept a single argument, so the contract error in the second case below makes sense.

Re: [racket-users] "bad variable linkage" after restarting handin server under load

I don't know what's going on here, but could it be that two threads are, in parallel, trying to load the same implementation of an unloaded checker and then stomping on each other? The file handin-server/private/reloadable has some dynamic-requires without appropriate syncronization around them,

Re: [racket-users] "bad variable linkage" after restarting handin server under load

Hi and thanks for reacting promptly! On 25 November 2015 at 13:52, Robby Findler wrote: > I don't know what's going on here, but could it be that two threads > are, in parallel, trying to load the same implementation of an > unloaded checker and then stomping on each

Re: [racket-users] "bad variable linkage" after restarting handin server under load

The stomping on I was worried about would happen at a lower-level as I don't think that, in general, dynamic-require is thread-safe. After all, it loads and runs arbitrary code, altho in this case it appears to be a system level lack of thread safety? I'm still not completely sure, but since you