Use deterministic $TMPDIR in sandbox
Use deterministic $TMPDIR in sandbox

Rather than using $<host-TMPDIR>/nix-build-<drvname>-<number>, the
temporary directory is now always /tmp/nix-build-<drvname>-0. This
improves bitwise-exact reproducibility for builds that store $TMPDIR
in their build output. (Of course, those should still be fixed...)

dtzWill/nix,layus/nix,pikajude/nix,vcunat/nix,NixOS/nix,layus/nix,ysangkok/nix,ehmry/nix,shlevy/nix,layus/nix,wmertens/nix,layus/nix,shlevy/nix,ysangkok/nix,dtzWill/nix,rycee/nix,wmertens/nix,rycee/nix,garbas/nix,garbas/nix,NixOS/nix,shlevy/nix,NixOS/nix,ehmry/nix,rycee/nix,dtzWill/nix,shlevy/nix,peti/nix,bennofs/nix,peti/nix,dezgeg/nix,ysangkok/nix,dezgeg/nix,garbas/nix,shlevy/nix,vcunat/nix,ttuegel/nix,ehmry/nix,bennofs/nix,wmertens/nix,peti/nix,rycee/nix,bennofs/nix,dezgeg/nix,dezgeg/nix,dtzWill/nix,zimbatm/nix,peti/nix,layus/nix,ehmry/nix,NixOS/nix,zimbatm/nix,peti/nix,dezgeg/nix,vcunat/nix,ehmry/nix,ttuegel/nix,zimbatm/nix,ehmry/nix,NixOS/nix,zimbatm/nix,ttuegel/nix,bennofs/nix,wmertens/nix,pikajude/nix,ttuegel/nix,pikajude/nix,garbas/nix,garbas/nix,vcunat/nix,rycee/nix,dtzWill/nix