Bug 728122 – media-libs/mesa-19.3.5 - ERROR: C++ Compiler does not support -std=c++14

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description EoD 2020-06-13 12:19:40 UTC]

Created attachment 644554 [details]
build.log

When I try rebuilding mesa-19.3.5
> [ebuild   R    ] media-libs/mesa-19.3.5::gentoo  USE="X classic d3d9 debug dri3 egl gallium gbm gles1 gles2 libglvnd llvm lm-sensors opencl vaapi vdpau vulkan wayland xvmc -osmesa -pax_kernel (-selinux) -test -unwind -valgrind -vulkan-overlay -xa" ABI_X86="32 (64) x32" KERNEL="(linux%*)" VIDEO_CARDS="i965 intel iris nouveau radeon radeonsi (-freedreno) -i915 (-lima) (-panfrost) -r100 -r200 -r300 -r600 (-vc4) -virgl (-vivante) -vmware" 0 KiB


I am getting the following error:

> Found ninja-1.9.0.git.kitware.dyndep-1.jobserver-1 at /usr/bin/ninja
> 
> ERROR: C++ Compiler does not support -std=c++14

Using 
> # gcc --version
> gcc (Gentoo 9.3.0 p2) 9.3.0

[Comment 1 Jeroen Roovers (RETIRED) 2020-06-16 08:06:03 UTC]

Please post your `emerge --info' output in a comment.

[Comment 2 Matt Turner 2020-06-16 20:14:12 UTC]

Also, please test 20.0.8 which has just been stabilized.

[Comment 3 EoD 2020-06-20 14:10:40 UTC]

Created attachment 645402 [details]
mesa-20.0.8-build.log

(In reply to Matt Turner from comment #2)
> Also, please test 20.0.8 which has just been stabilized.

Same problem with 20.0.8. Please note, that I tried to *re*build mesa 19.3.5. It was compiled successfully before.

[Comment 4 EoD 2020-06-20 14:11:41 UTC]

Created attachment 645404 [details]
emerge_info.log

(In reply to Jeroen Roovers from comment #1)
> Please post your `emerge --info' output in a comment.

Attached

[Comment 5 EoD 2020-06-20 14:52:12 UTC]

Created attachment 645408 [details]
mesa-20.0.8-build-successful.log

Update: I got it to build with the following steps

1. Reboot Gentoo
2. Building mesa: causes the aforementioned failure
3. Building mesa again: works successfully (logs attached).


Most notably, the difference between those two builds starts with a lot of "__attribute__" checks (they are NO on the first run and YES on the second run):

> Checking if "__attribute__((const))" compiles: YES  
> Checking if "__attribute__((flatten))" compiles: YES  
> Checking if "__attribute__((malloc))" compiles: YES  
> Checking if "__attribute__((pure))" compiles: YES  
> ...

[Comment 6 Matt Turner 2020-07-30 20:25:55 UTC]

I assume that this was fixed by this?

https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4948

[Comment 7 EoD 2020-09-04 14:30:42 UTC]

(In reply to Matt Turner from comment #6)
> I assume that this was fixed by this?
> 
> https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4948

Is this version already in the Gentoo tree?

I still have the problem with Mesa 20.0.8 in the Gentoo tree.

[Comment 8 Matt Turner 2020-09-04 17:35:09 UTC]

No, it's not in 20.0.8, but it's in later versions.

I don't understand, did you not review the patch in that gitlab MR?

[Comment 9 EoD 2020-09-06 14:23:38 UTC]

(In reply to Matt Turner from comment #8)
> No, it's not in 20.0.8, but it's in later versions.
> 
> I don't understand, did you not review the patch in that gitlab MR?

No, I did not review this patch. 

If the question is, if I am using PowerPC:
No, I am using a Intel Skylake.

I went ahead and applied the patch (slightly modified) on top of my mesa-20.0.8 installation and I am still seeing the same error during the first build.

[Comment 10 Matt Turner 2020-11-19 20:09:43 UTC]

Is this still a problem with mesa-20.2 or mesa-20.3?

[Comment 11 EoD 2020-12-12 00:49:24 UTC]

(In reply to Matt Turner from comment #10)
> Is this still a problem with mesa-20.2 or mesa-20.3?

I am unable to reproduce the failure with media-libs/mesa-20.2.4.

I also uninstalled ccache recently, maybe this is was actually a ccache problem in the first place.