Sorry, been working on this for the past few days actually.
I just pushed a bunch of commits all at once, rebuilding starting with core's gcc. I re-did all the modifications I've made that weren't pushed yet, in small commits to show small steps, hoping to find a mistake. (BTW, only the most recent pushed commit has a rebuilt .SRCINFO, as the other commits pushed with it at the same time were intended to show steps, and not necessarily be valid within themselves, or be intermediary places to actually use.)
After fixing the issue described below, I will update to use isl-0.20. (Doing so has no effect on the error.) I wouldn't be surprised if there's one or two other modifications to make to actually build the package. (Previously, provides gave basever, this is trying out a full pkgver, etc.)
If I manually follow the steps in the PKGBUILD (run everything in prepare(), the exact same configure, and make) it compiles correctly, and gets me manually to where the end of the PKGBUILD's build() would be.
If I run extra-x86_64-build (devtools, my preference), or even makepkg, it fails to compile, with the error below. This is before the PKGBUILD's build() finishes, specifically in running plain "make".
I've been quite confused. My next step is to look through what makepkg is doing, and hopefully figure out how to reproduce the failure manually and if needed figure out if it's possible to perform an efficient bisect. I'll also be posting on the PKGBUILD forums. Might reach upstream, but I'm not thinking the issue lies there since it compiles just fine outside of makepkg.
I don't know how the other AUR building tools will do, until this is fixed. I wouldn't be surprised if they all use makepkg at some point, so my bet is they will fail.
Using makepkg or extra-x86_64-build (devtools), I get this compilation error in stage 3 of the build (which is a verification step of gcc's build process.)
Full build error here (too hard to post here, AUR takes too much of it as formatting): https://pastebin.com/28dYQqrk
=====
/build/gcc-git/src/gcc/gcc/config/i386/i386.c:19200:1: error: invalid operand in unary operation
19200 | output_fix_trunc (rtx_insn insn, rtx operands, bool fisttp)
| ^~~~~~~~~~~~~~~~
/build/gcc-git/src/gcc/gcc/config/i386/i386.c:19200:1: error: incorrect sharing of tree nodes
(ssizetype) _19
_58 = (long unsigned int) ((ssizetype) _19 <= 7 ? 7 - (ssizetype) _19 : 0);
/build/gcc-git/src/gcc/gcc/config/i386/i386.c:19200: confused by earlier errors, bailing out
make[3]: *** [Makefile:2287: i386.o] Error 1
Pinned Comments
jamespharvey20 commented on 2017-02-15 04:30
*** STICKY ***
These gcc*-git packages replace core's gcc* (non-git) packages. Technically, replacing the system gcc-libs can be dangerous. The possibility of a new upstream gcc git commit breaking your system isn't zero. When you compile and install this, you're using the latest git source, so you may be the first Arch user to be using that particular commit.
In practice, I haven't seen an Arch user report such a problem for many years. Just understand that if installing these packages causes your computer to eat you, don't have your loved ones blame me. Oh, and know that if things go wrong, all you *should* have to do is uninstall the git version and go back to a previously working git version or even the core version. You might be able to do this while your system is still running, or you might have to do something like boot off an Arch ISO CD.