Mark H Weaver writes: > Giel van Schijndel writes: > >> The problem seems to be triggered by glibc appearing on the search path. >> >> I'm not sure about GCC's internals exactly so I'm making one assumption >> that causes all of this to make sense to me: if a directory appears >> multiples times in the search path it will be searched only the first >> time that it's encountered. >> >> So in short: contains an "#include_next " >> preprocessor directive. That's a GCC extension that tells the >> preprocessor it should only search directories appearing in the search >> path _after_ the directory containing the file currently being processed. > > I ran into the same problem with our 'gjs' package in the 'core-updates' > branch. First I added 'gcc-7' to the inputs to work around a different > issue (an internal compiler error in gcc-5), and then I encountered the > exact problem you described above. > > On my own private branch, I worked around this problem by adding > "-idirafter /include" to CXXFLAGS, but of course it's not a proper > fix. My workaround happens to be in Savannah on the > 'reproduce-bug-29774' branch: > > https://git.savannah.gnu.org/cgit/guix.git/commit/?h=reproduce-bug-29774&id=87022e2666c5e68e865eb160a4bd8e9cdcc1a955 I forgot to mention that in addition to adding -idirafter, I also had to remove /include from CPLUS_INCLUDE_PATH. Without the latter, the -idirafter directive was ignored as a duplicate. Mark