After getting a private email about what caused PR 29049 for real, I noticed that the prerequisite for awk was not documented in http://gcc.gnu.org/install/prerequisites.html
Yes it is a standard UNIX tool but there are some versions of GNU awk which are broken. -- Summary: awk Prerequisite is not documented Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: documentation Severity: normal Priority: P3 Component: bootstrap AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pinskia at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30739