Thanks for the bug report.
I can reproduce a nonconvergence of ZGGEV for the pencil you provided. This confirms what you are saying. Nice pencil, thanks . . .
Your pencil is made of two complex symmetric tridiagonal matrix. (I do mean complex symmetric, I do not mean Hermitian.) I guess you knew that.
1) Matlab is working (as you mentioned).
2) The error INFO is 481 on my computer using the svn-up-to-date LAPACK and associated reference BLAS,
3) The error INFO is 454 (so a little better) on my computer using the svn-up-to-date LAPACK and vecLib BLAS,
4) The error INFO is 454 (so a little better) on my computer using vecLib LAPACK+BLAS
=> bug 116 is confirmed.
Victor, what is your error INFO? (Just for fun . . . )
MathWorks is using a Nonsymmetric Generalized Eigensolver which is based on LAPACK, but is improved. This is Cleve Moler's legacy I guess there. We are in contact with MathWorks, and we are trying to synch our version with theirs. We did this a few times ago but I guess we did not fully do it since there seem to still be some problems in LAPACK which are not in MathWorks version. Shoo . . . Well, we will need to look in to this.