stdenv_32bit.gcc is broken, breaking e.g. virtualbox

[sjau]

Issue description

Virtualbox fails to compile

/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
/tmp/nix-build-cuneiform-1.1.0.drv-0/cuneiform-linux-1.1.0/cuneiform_src/Kern/std/src/stdprt.cpp:98:4: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

  Cannot execute 32-bit applications! Either enable 32-bit support in the
  kernel configuration or use --disable-vmmraw to disable 32-bit guests.
Check /tmp/nix-build-virtualbox-5.0.14-4.4.6.drv-0/VirtualBox-5.0.14/configure.log for details
builder for ‘/nix/store/x3ngqp09rlc8jmsvz0v31sjidpcqfmg4-virtualbox-5.0.14-4.4.6.drv’ failed with exit code 1
cannot build derivation ‘/nix/store/nngkx78dk7gd16k1byqn34ffsl92j04x-nixos-system-subi-16.09pre79976.cb44efc.drv’: 1 dependencies couldn't be built
error: build of ‘/nix/store/nngkx78dk7gd16k1byqn34ffsl92j04x-nixos-system-subi-16.09pre79976.cb44efc.drv’ failed

Steps to reproduce

Use unstable small repo

Technical details

• System: (NixOS: nixos-version, Ubuntu/Fedora: lsb_release -a, ...)

16.09pre79294.c58c1f3 (Flounder)

• Nix version: (run nix-env --version)

nix-env (Nix) 1.11.2

[jcumming]

When I looked quickly, the 32b toolchain was setting the interpreter be the 64b ld.so.

[vcunat]

http://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.linuxPackages.virtualbox.x86_64-linux
I think the multi-bit toolchain is broken since merging #14000.

[domenkozar]

Note: this is blocking channel update for trunk-combined.

[obadz]

cc @nbp

[obadz]

also cc-ing vbox maintainer @svanderburg

[vcunat]

Interesting, gcc produces a 32-bit executable but sets a 64-bit interpreter to it:

$ nix-build -Q -A stdenv_32bit.cc
$ ./result/bin/gcc -m32 ../tests/hello.c
$ file a.out 
a.out: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /nix/store/k2pbdqpql203amyi3rn8as5kwskkaqc1-glibc-multi-2.23/lib/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, not stripped

I've got no idea why that would happen, especially in connection with merging that PR.

[abbradar]

@vcunat Can you do the same but with NIX_DEBUG on? Might show up something.

[vcunat]

Right, it confirms my suspicion – we pass the wrong loader explicitly.

[vcunat]

Oh, I see... this should be fixed by a staged commit 6c9ce23. Let me check it.

[vcunat]

Fortunately we have those in binary cache, and my hello example works fine there :-)

[vcunat]

Looking at the branch status, I expect we can merge it soon – I see no big regressions and there are just ~12k jobs in queue. http://hydra.nixos.org/eval/1252653#tabs-now-fail

[abbradar]

Ouch, sorry again for breaking this D:

[nbp]

@vcunat I do not think this is #14000, as I verified that I got the same checksums, and this also includes some pkgsi686 packages. Otherwise, if I am wrong, a bisect should tell you which commit caused the problem.

I guess this is more likely to be the stdenv merge which happened after #14000. In which case we might also have the problem on 16.03.

[vcunat]

@nbp: we found the cause of the problem in the meantime (above) and it was something different that was merged about the same time (but it didn't get into 16.03).

[vcunat]

It builds on master now.