On 8/30/16 Aug 30 -3:46 PM, Jason Miller wrote: > On 09:48 Mon 29 Aug , Kevin Layer wrote: >> I've avoided getting into this discussion, but I feel I need to ask: >> why use *load-truename* instead of *load-pathname*? >> >> *load-truename* goes through symbolic links (even though the ANS says >> nothing about it, this is the behavior of implementations I know of) >> and that is almost always the wrong thing. GNU make doesn't do it, I >> don't see why ASDF should do it. A build system should never itself >> follow symlinks, because it defeats systems that have been in place >> for 30+ years: linked directories of binary files linking to a single >> source directory. > Somewhat off-topic, but I'll bite: > > This is because *load-pathname* is likely to be a relative pathname, and > relative pathnames have their own problems. The unix way of solving it > is to transform relative pathnames with "$PWD/pathname" but I don't > believe there is a builtin facility for doing the equivalent in common > lisp, nor did I find one in a quick look throug uiop/pathname. >
There is a method for doing this, but it's done through *default-pathname-defaults* The problem is that the Unix way relies on the current working directory, but *default-pathname-defaults* is populated in a domain-dependent way. Rant: As with non-CL software, it's amazing how many people assume that you will be running their software in the way they do, typically from the directory where the code is located. I cannot tell you how much aggregate time I have spent over the years hardening other people's software against violations of this assumption. Please folks, remember that even *I* may not know the working directory of my SLIME instance, so *you* cannot count on it!
