configure.env variables overwritten between pre-configure and configure stages

[michaelld@…]

See ticket #25320 comment 3 and 4. This overwriting might also occur between other pre- and regular stages; I haven't checked for those.

[michaelld@…]

Given our discussion about header include paths on the macports-dev list, I think the qt4-mac Portfile (for the most part) is correct in using the CPATH to specific where headers are located. Hence, this ticket becomes a high priority, as this issue seems to be truncating the configure environment variables (at least CPATH and LIBRARY_PATH) such that some ports may not configure correctly. I have no idea where to look to fix this issue.

[jmr@…]

You're not meant to use *.env when there is a specific variable available for that purpose. For example, you use configure.cc instead of setting CC in configure.env. In this case, you want compiler.cpath and compiler.library_path.

[michaelld@…]

Had no idea those configure. variables existed, so I'll try using them & see if that takes care of the issue.

[michaelld@…]

Do those same .variables exist for the other phases (e.g., build, destroot, etc..)? I need them for at least build.

[michaelld@…]

Sorry; just reread that you wrote "compiler." instead of "configure." ... so ignore that last comment.

[michaelld@…]

Yes, I realized that this ticket is closed, but I want to correct the info for future reference.

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Playing with the compiler.cpath (via the qt4-mac Portfile), it looks like what was going on is:

(0) environment variable CPATH was being set in configure.env correctly. Yes, I know this is the not the correct way to do it, but that's the way the Portfile has worked for quite a while now; I'm just inheriting its behavior.

(1) compiler.cpath was not being set, and so defaults to "${prefix}/include" alone (without ""s).

(2) when creating the environment for the 'configure' stage, the compiler.cpath entirely overwrites whatever is in the configure.env's CPATH variable.

I don't know if the above is desirable behavior or not, but: Given that qt4-mac worked by setting the configure.env CPATH variable once upon a time, the above represents a change in Portfile interpretation that was (AFAICT, stealthily) detrimental to the qt4-mac port -- and might be to other ports as well.

Is it possible to modify whatever routine is tweaking the configure.env (or XX.env) between the 'pre-configure' and 'configure' stages (or 'pre-build' and 'build', etc), such that it either (1) merges the CPATH (or other variable, etc) from both the compiler.cpath (etc) and the configure.env; or (2) prints out a warning that the CPATH (etc) variable is being overwritten, and to use compiler.cpath (etc) instead? Either might be a tall order, but something needs to happen IMHO: stealthily overwriting will only add confusion to Portfile behavior.