When building older versions of gcc (2.7 and perhaps some early 2.8) on a hppa*-*-hpux10 platform, the `fixincludes' step (which involves running a sed script) fails because of a bug in the vendor's implementation of sed. The workaround is to install GNU sed before building gcc. The file sed-2.05.bin.hpux10 is a precompiled binary for that platform. However, newer versions of gcc are believed to properly deal with the broken sed, so this shouldn't be necessary anymore.