<angerman>
setting TMPDIR=/tmp prior to invoking nix-build does work, but obviously is not correct.
<angerman>
couldn't we use `mktemp -d` instead?
<LnL>
what kind of setup? a multiuser install won't use the long TMPDIR
<angerman>
LnL: single user. But Apparently I can't get it to pick that up in any form what so ever, even though the derivation that fails to build has TMPDIR=... set
<LnL>
yeah single user would use the per-user prefix
<angerman>
LnL: ok. But if I set `TMPDIR` in the derivation (as we do for darwin in the nix derivation), why wouldn't it pick it up then?
<angerman>
As I understood that had to do with single user mode? Though I believe I'm missing something.
<LnL>
nix itself creates NIX_BUILD_TOP, the root where the build will be performed
<angerman>
LnL: Ok. Now I'm even more confused.
<angerman>
I thought setting TMPDIR would allow us to provide an alternative directory, and thus help with the length of the path?
<LnL>
single user mode inherits TMPDIR from the login user, which has a long prefix
<LnL>
but with multi-user the client doesn't send this to the daemon, and the daemon deices where the prefix is
<angerman>
LnL: ok, maybe I'm coming to an understanding here. The test that fail involve multi-user (we run export NIX_REMOTE=daemon), and as such we have no way to force a different TMPDIR? And as such are doomed to always fail the tests on darwin?
<LnL>
the tests themselves also rely on TMPDIR (which is never set) so it creates /tmp/nix-test by default
<angerman>
even if my preInstallCheck is set to `export TMPDIR=/tmp`, I end up with `error: socket path '/private/var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/tmp.RmbjD1Vp/nix-build-nix-2.2.2.drv-0/tmp.0BMj4FY5RC/nix-test/var/nix/daemon-socket/socket' is too long`?
<LnL>
this is not unique and owned by one of the nixbld users, if any other nixbld user tries to build nix later it won't have permissions
<LnL>
oh that's odd, perhaps ./configure already decides where to put this?
<angerman>
I even tried to add a TMPDIR="/tmp" to the nix derivation. Still no help.
<angerman>
it's as if the test suite cleans TMPDIR or something.