On 8/31/16 Aug 31 -11:43 AM, Robert Goldman wrote: > On 8/31/16 Aug 31 -11:26 AM, Kevin Layer wrote: >> 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, .. >> >> This is certainly not true in Allegro. In lisps where it is true, >> it's easily fixable with (merge-pathnames *load-pathname*). >> > > I suppose this is safe, but I always have an unpleasant feeling about > using a function call like this that depends on the value of a special > variable (*default-pathname-defaults*) that I don't control. > > At any rate, we pretty much established that in an ASDF-loaded system, > *load-pathname* is likely to be garbagy, because at load time it > typically holds the pathname of the *RELOCATED* FASL file, which is of > no use to anyone.
This issue just popped up on the LispWorks users group mailing list, so I took a few minutes to write a FAQ about it, and pushed it into the manual. I have updated the manual version on the ASDF web page at common-lisp.net to hold the new version. Comments welcome.
