1294157 - Build failure with "ac_add_options --enable-stdcxx-compat": TEST-UNEXPECTED-FAIL | check_stdcxx | We do not want these libc symbol versions to be used: memcpy@GLIBC_2.14, clock_gettime@GLIBC_2.17

Status: RESOLVED INVALID

(Firefox Build System :: General, defect)

Description

[Daniel Holbert [:dholbert]]

[I just triggered a footgun when using an older mozconfig of mine, and figured I'd file a bug.]

STR:
 (1) Add ac_add_options --enable-stdcxx-compat to your mozconfig.
 (2) Try to build.

ACTUAL RESULTS:
The following build failure:
> libnspr4.so
> TEST-UNEXPECTED-FAIL | check_stdcxx | We do not want these libc symbol versions to be used:
>   memcpy@GLIBC_2.14
>   clock_gettime@GLIBC_2.17
> $SRC/config/rules.mk:816: recipe for target 'libnspr4.so' failed
> make[5]: *** [libnspr4.so] Error 1
> make[5]: *** Deleting file 'libnspr4.so'

Perhaps my answer here is "Don't put that in your mozconfig". :)  But, the build failure made me wonder -- is this build option still supported, and is it still useful?  If not, perhaps we just drop it?

(It looks like the last time we touched this option was in 2011, when we made it opt-in instead of opt-out, in bug 650467.)

I'm using 64-bit Ubuntu 16.04, BTW.

Comment 1

[Mike Hommey [:glandium]]

It's used on automation, for the mozilla.org-produced linux builds. It's what makes our gcc-4.8 glibc-whatever built binaries work on distros with older libstdc++ and glibc than that. And the check validates that that compatibility is still guaranteed.

If you build on Ubuntu 16.04, no amount of the hacks the flag enables is going to make the resulting binary compatible with those old libstdc++ and glibc, thus the error you see.

IOW: this is not an option for people to use.