I removed cblas-reference with 'emerge -v --depclean cblas-reference'. The subsequent 'emerge -p @preserved-rebuild' want to reinstall the following packages: root@sysresccd:/(4)# emerge -p @preserved-rebuild These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild R ] sci-libs/arpack-3.1.5 [ebuild R ] sci-libs/armadillo-6.700.5 [ebuild R ] sci-libs/iml-1.0.5 [ebuild R ] sci-libs/linbox-1.3.2-r2 [ebuild R ] sci-libs/cholmod-2.1.2 [ebuild R ] sci-mathematics/sage-7.2 ... The reinstallation atleast of arpack fails due to missing lapack: root@sysresccd:/(12)# MAKEOPTS=-j1 emerge -v1 arpack These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild R ] sci-libs/arpack-3.1.5::gentoo USE="doc examples -mpi -static-libs" 0 KiB ... checking for dummy main to link with Fortran 77 libraries... none checking for Fortran 77 name-mangling scheme... lower case, underscore, no extra underscore checking for sgemm_ in -lf77blas... yes checking for cheev_... no checking for cheev_ in -llapack... no checking for cheev_ in -llapack_rs6k... no configure: error: Cannot find LAPACK libraries I have atlas and mkl installed: root@sysresccd:/(15)# qlist -Iv atlas mkl sci-libs/atlas-3.11.38-r1 sci-libs/mkl-11.3.2.181 eselect-lapack is not installed and I can not installe it due to conflicts with several other packages: root@sysresccd:/(13)# qlist -Iv eselect-lapack root@sysresccd:/(14)# emerge -pv1 eselect-lapack These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild N ] app-eselect/eselect-lapack-0.1::gentoo 0 KiB [blocks B ] app-eselect/eselect-lapack ("app-eselect/eselect-lapack" is blocking sci-libs/gsl-2.1, virtual/lapack-3.6, sci-libs/mkl-11.3.2.181) [blocks B ] app-eselect/eselect-lapack ("app-eselect/eselect-lapack" is blocking sci-libs/atlas-3.11.38-r1) Total: 1 package (1 new), Size of downloads: 0 KiB Conflict: 2 blocks (2 unsatisfied) * Error: The above package list contains packages which cannot be * installed at the same time on the same system. (sci-libs/mkl-11.3.2.181:0/0::science, installed) pulled in by sci-libs/mkl required by (sci-libs/armadillo-6.700.5:0/6::science, installed) sci-libs/mkl required by (dev-python/numexpr-2.5:0/0::gentoo, installed) sci-libs/mkl[int64?,abi_x86_32(-)?,abi_x86_64(-)?] (sci-libs/mkl[abi_x86_64(-)]) required by (virtual/blas-2.1-r5:0/0::science, installed) sci-libs/mkl[int64?,abi_x86_32(-)?,abi_x86_64(-)?] (sci-libs/mkl[abi_x86_64(-)]) required by (virtual/lapack-3.6:0/0::science, installed) (app-eselect/eselect-lapack-0.1:0/0::gentoo, ebuild scheduled for merge) pulled in by eselect-lapack (sci-libs/atlas-3.11.38-r1:0/0::science, installed) pulled in by sci-libs/atlas[lapack] required by (sci-libs/armadillo-6.700.5:0/6::science, installed) (sci-libs/gsl-2.1:0/19::science, installed) pulled in by sci-libs/gsl required by (sci-mathematics/gmp-ecm-6.4.4-r2:0/0::sage-on-gentoo, installed) sci-libs/gsl:0= required by (dev-python/cvxopt-1.1.8:0/0::sage-on-gentoo, installed) >=sci-libs/gsl-1.15 required by (media-video/guvcview-2.0.3:0/0::gentoo, installed) ... (virtual/lapack-3.6:0/0::science, installed) pulled in by =virtual/lapack-3.6 required by (sci-libs/arpack-3.1.5:0/0::gentoo, installed) virtual/lapack required by (sci-libs/cholmod-2.1.2:0/0::gentoo, installed) virtual/lapack required by (dev-python/cvxopt-1.1.8:0/0::sage-on-gentoo, installed) ... I tried to reemerge mkl, which fails due to bug https://bugs.gentoo.org/show_bug.cgi?id=587338. I will now try to reemerge atlas.
You are using the science overlay. lapack from the science overlay uses the alternatives framework inside eselect. It doesn't use a separate `eselect-lapack` module. It looks like you have atlas eselected for blas but nothing for lapack. What does eselect lapack list reports?