Build started to fail with 1.10

[Владислав Митов]

Hey guys, 

One of my build started failing with 1.10. Basically I'm building a wrapper around a C library and it fails with: 

# runtime/cgo
gcc_libinit.c: In function '_cgo_try_pthread_create':
gcc_libinit.c:97:18: error: storage size of 'ts' isn't known
  struct timespec ts;
                  ^~
gcc_libinit.c:110:3: error: implicit declaration of function 'nanosleep' [-Werror=implicit-function-declaration]
   nanosleep(&ts, nil);
   ^~~~~~~~~
gcc_libinit.c:97:18: error: unused variable 'ts' [-Werror=unused-variable]
  struct timespec ts;
                  ^~
cc1: all warnings being treated as errors

https://travis-ci.org/miracl/gomiracl/jobs/344782123

Any hint's what's causing this? 

Cheers, 

Vladi

[Ian Lance Taylor]

You say this started failing with 1.10. That file
(runtime/cgo/gcc_libinit.c) hasn't changed since 1.9, so I think
something else must have changed.

timespec and nanosleep are normally defined in <time.h>. What system
are you using?

Ian

[Владислав Митов]

I'm not sure where the issue is but I tried with 1.9 - both locally and in Travis it passes with the same code. 
https://github.com/miracl/gomiracl/compare/fix-build?expand=1 - code 

https://travis-ci.org/miracl/gomiracl/jobs/345000314 - build

[Nic Pottier]

This is almost certainly because your .travis file is specifying your version as `1.10` vs `"1.10"`

So your build is building with go 1.1 instead of 1.10.

Ran into this myself this morning.

-Nic

[Владислав Митов]

Ah, I read about that but ti says `go version go1.10 linux/amd64`. I'll try putting it in quotes now.

[Владислав Митов]

Nah, it's not that - https://travis-ci.org/miracl/gomiracl/jobs/345158452. If fails also in golang:latest where the yaml gotcha it's not a thing. Solid suggestion though, thanks.

[Dave Cheney]

The failing line was added in december last year,

https://github.com/golang/go/commit/7cba779cea5#diff-56c7df71bce32f8e50115128ae30941eR13

This also adds a dependency on time.h. Is time.h available in your build container?

[Vladislav Mitov]

Not sure, I'l building in golang:latest https://github.com/miracl/gomiracl/blob/master/Dockerfile#L23.

[Vladislav Mitov]

Interesting fact is that if I remove "-std=c99" from CGO_CFLAGS it works locally, fails in Travis though.

[adam.a...@10xgenomics.com]

I've run into this as well.  It looks somewhat related to

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=314435

As the maintainers explained there, nanosleep isn't part of the c99 standard (it is part of the posix standard).

When you set -std=c99, that turns off -D_GNU_SOURCE, which turns off _POSIX_C_SOURCE in features.h, which turns off nanosleep, amongst other things.  Not clear on exactly why this didn't matter in go 1.9, however.