Currently, when installing two versions/copies of GCC into the same prefix, using suitable --libdir, --infodir and --program-suffix options, the *only* conflict, that is, the only file the second copy of GCC will overwrite, is lib/pkgconfig/libgcj.pc.
One approach would be putting this into a version-specific subdirecty, such as --libdir, or name the file libgcj41.pc, libgcj42.pc, etc. -- Summary: lib/pkgconfig/libgcj.pc needs to become version dependent Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: major Priority: P3 Component: libgcj AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: gerald at pfeifer dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29205