On Fri, Sep 18, 2020 at 02:10:13PM -0600, Ian Lepore wrote: > On Fri, 2020-09-18 at 15:44 -0400, Mark Johnston wrote: > > On Fri, Sep 18, 2020 at 01:27:23PM -0600, Ian Lepore wrote: > > > On Fri, 2020-09-18 at 19:03 +0000, Mark Johnston wrote: > > > > Author: markj > > > > Date: Fri Sep 18 19:03:34 2020 > > > > New Revision: 365889 > > > > URL: https://svnweb.freebsd.org/changeset/base/365889 > > > > > > > > Log: > > > > Install library symlinks atomically. > > > > > > > > As we do for shared library binaries, pass -S to install(1) when > > > > installing symlinks. Doing so helps avoid transient failures when > > > > libraries are being reinstalled, which seems to be the root cause > > > > of > > > > spurious libgcc_s.so link failures during CI builds. > > > > > > > > > > Actually, I believe this will just paper over the real problem, which > > > is the fact that we're building and installing the same library > > > multiple times during early build steps. Nobody has yet been able to > > > explain why we do that, and I haven't been able to figure out why by > > > analyzing any differences in the generated files, but I'm not done > > > trying. > > > > Sorry, this deserved more commentary in the commit log. > > > > Indeed, we install libgcc_s.so multiple times during buildworld. As far > > as I can see, it's intentional insofar as libgcc_s.so is listed in > > multiple library targets: it's in both _prereq_libs and _startup_libs in > > Makefile.inc1. In particular, from scanning the log from a recent > > instance of the failure, libgcc_s gets built once but installed multiple > > times. > > > > Why that's the case, or whether it's still necessary, is not clear to > > me. But adding -S seemed like a desirable change in general, so I went > > forward with it. > > Yeah, it has been listed in both prereq and startup list since it was > first added by kan@ in 2007 or so. I wonder if he remembers why (added > to cc list)?
Digging a bit deeper, _prereq_libs are built with -DNO_PIC. For lib/libgcc_s this actually does nothing: libgcc_s/Makefile does not define LIB so no static library gets built. The problem seems to be that libgcc_s gets built+installed for _startup_libs and then again as part of _generic_libs. Again, the constituent object files only get built once, but the library binary and symlink get installed multiple times into the worldtmp dir. libc.so is not a symlink and was already getting installed with -S, so despite also getting installed to worldtmp multiple times it does not cause similar build failures. So it seems that: - libgcc_s can be dropped from _prereq_libs. - _generic_libs revisits libraries that were built during earlier stages of the libraries target, i.e., the problem is not specific to libgcc_s. _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
