Since commit fb777be7d2925ec0e97783ce5e3a0136361dc0a8, linking programs
in /tmp will no longer work, since with this commit (hardcoded) /tmp
will no longer be treated a valid temporary directory by the purity
checking logic.
Essentially what that logic does is checking whether the link target is
either relative, in some temporary directory or in the Nix store and if
that's not the case, an error is thrown like in this case:
gcc -c /tmp/build.24.tmp.c -o /tmp/build.24.tmp.c.o
gcc /tmp/build.24.tmp.c.o -o /tmp/build.24.tmp.out
impure path `/tmp/build.24.tmp.out' used in link
collect2: error: ld returned 1 exit status
Note here, that $TMP and $TMPDIR point to /build while the output here
still refers to /tmp. This is because the custom build system of uqm
simply hardcodes /tmp and doesn't honor any of these variables.
To fix this, all we need to do is the latter and we're now using $TMPDIR
instead of /tmp for these compile-tests during configure.
While the pull request[1] introducing said commit has a few comments
regarding other issues and it could still be either reverted or changed,
using $TMPDIR in the uqm build script is entirely backwards-compatible
and shouldn't hurt in any case.
[1]: https://github.com/NixOS/nixpkgs/pull/93560
Signed-off-by: aszlig <aszlig@nix.build>
948d828955