https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65998
Bug ID: 65998 Summary: please support multiarch for the user search paths (CPATH, etc.) Product: gcc Version: 5.1.1 Status: UNCONFIRMED Severity: enhancement Priority: P3 Component: preprocessor Assignee: unassigned at gcc dot gnu.org Reporter: vincent-gcc at vinc17 dot net Target Milestone: --- cpp currently supports multiarch search paths for /usr/local and /usr, but not for directories supplied via environment variables like $CPATH and $C_INCLUDE_PATH. For instance, "cpp -v" gives: /usr/local/include/x86_64-linux-gnu /usr/local/include [...] /usr/include/x86_64-linux-gnu /usr/include and when adding the -m32 option: /usr/local/include/i386-linux-gnu /usr/local/include [...] /usr/include/i386-linux-gnu /usr/include But if I use CPATH=/home/vlefevre/include, I just get: /home/vlefevre/include in the cpp output (while the subdirectories /home/vlefevre/include/x86_64-linux-gnu and /home/vlefevre/include/i386-linux-gnu exist too). Adding the other subdirectory to $CPATH is not a good solution because one doesn't always know the ABI (whether -m32 is present or not) in advance, i.e. one doesn't know in advance which directory to add to $CPATH.