Stop building with -Werror

[nalimilan]

-Werror should not be used in default build flags as it makes the compilation fail every time somebody tries to build with a new version of the compiler which triggers a new warning. It should only be set when running CI.

I saw this when trying to build the RPM for Julia 1.8.0-rc3 on Fedora rawhide (with GCC 12.1.1):

threading.c: In function 'lbt_register_thread_interface':
threading.c:44:5: error: 'strcpy' writing one too many bytes into a region of a size that depends on 'strlen' [-Werror=stringop-overflow=]
   44 |     strcpy(getter_names[idx], getter);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
threading.c:43:34: note: destination object of size [0, 9223372036854775805] allocated by 'malloc'
   43 |     getter_names[idx] = (char *) malloc(strlen(getter));
      |                                  ^~~~~~~~~~~~~~~~~~~~~~
threading.c:46:5: error: 'strcpy' writing one too many bytes into a region of a size that depends on 'strlen' [-Werror=stringop-overflow=]
   46 |     strcpy(setter_names[idx], setter);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
threading.c:45:34: note: destination object of size [0, 9223372036854775805] allocated by 'malloc'
   45 |     setter_names[idx] = (char *) malloc(strlen(setter));
      |                                  ^~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[1]: *** [Makefile:37: build/threading.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make[1]: Leaving directory '/builddir/build/BUILD/julia-1.8.0-beta3/deps/scratch/blastrampoline-d32042273719672c6669f6442a0be5605d434b70/src'
make: *** [/builddir/build/BUILD/julia-1.8.0-beta3/deps/blastrampoline.mk:14: scratch/blastrampoline-d32042273719672c6669f6442a0be5605d434b70/build-compiled] Error 2
make: Leaving directory '/builddir/build/BUILD/julia-1.8.0-beta3/deps'

The warning probably deserves some attention but the problem isn't new I guess so there's no reason to worry the particular user who happened to build with a new compiler version.

[ViralBShah]

Merge?

[staticfloat]

We should add this back on in CI as a part of this PR then.

[nalimilan]

I've added a commit which seems like it should have done that, but the logs show that the compiler was called without -Werror. Any ideas?

[giordano]

I think flags are overridden at

libblastrampoline/test/utils.jl

Lines 64 to 68 in b829b0e

	cflags_add = needs_m32() ? "-m32" : ""
	dir = mktempdir()
	srcdir = joinpath(dirname(@__DIR__), "src")
	run(`$(make) -sC $(pathesc(srcdir)) CFLAGS=$(cflags_add) ARCH=$(Sys.ARCH) clean`)
	run(`$(make) -sC $(pathesc(srcdir)) CFLAGS=$(cflags_add) ARCH=$(Sys.ARCH) install builddir=$(pathesc(dir))/build prefix=$(pathesc(dir))/output`)

[nalimilan]

Thanks, seems to work now!

[giordano]

Looks good to me, but I think the setting of cflags can be simplified in tests

[nalimilan]

Should be good now.

[giordano]

Side note, I think the warning was fixed by #71, right?

[staticfloat]

Thanks, @nalimilan!