On line 188 of ilaenv.c, only the first character of the subroutine name is copied, so later on when the name is tested against known sub names, the tests fail and always return a block size of 1. I just doubled checked this in the official clapack-3.2.1-CMAKE.tgz download. However, I just ran a relatively new version of f2c on the vanilla lapack-3.2.1 fortran source and it produces code which copies all 6 characters over.
Edit: Actually, all of the ftnlen parameters for c2, c3, and c4 are wrong. They are all 1 when they should be 2,3,2, respectively.