Comment (by Roland Haas):

Most likely I will revert git hash 22ffa3c "BLAS: use bash_utils.sh to search for library" of ExternalLibraries-BLAS and git hash 4e216f4 "LAPACK: use bash_utils.sh to search for library" of ExternalLibraries-LAPACK since BLAS and LAPACK handle BLAS_DIR and LAPACK_DIR in a way not supported by bash_utils. After the 2020_11 release I will propose to change how BLAS_DIR and L APACK_DIR are handled along with proposing a better defined behaviour for ExternalLibraries.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2476/blas-and-lapac-externallibraries-ignore