Hi, attached you find a patch for matplotlib. For python2-matplotlib I've noticed a behavior that I do not understand: matplotlib depends on numpydoc which I pushed yesterday and appears not to be ready yet on hydra. If I build python2-matplotlib with ./pre-inst-env guix build python2-matplotlib guix tells me that it will build among other packages /gnu/store/gjfrir5iykxwxicp9dxjv3adk5vpifb4-python2-numpydoc-0.5.drv However, the build process for this package fails, because a test fails. Since I prepared the numpydoc package I know about this test and know that the package includes the parameter #:tests? #f. In fact, if I explicitly build python2-numpydoc with ./pre-inst-env guix build python2-numpydoc it finished successfully (skipping the tests). The two ways of causing numpydoc to be built (direct and indirect) generate two independent /gnu/store/...-python2-numpydoc-0.5-guile-builder The one generated by an explicit build command includes the #:tests? #f flag as expected. However, the indirect one includes a #:tests? #t flag! I'm confused. Am I missing something? Here the definition of python2-numpydoc: (define-public python2-numpydoc (package (inherit (package-with-python2 python-numpydoc)) ;; With python-2 1 test (out of 30) fails because it doesn't find ;; matplotlib. With python-3 it seems to detect at run-time the absence ;; of matplotlib. (arguments `(#:tests? #f #:python ,python-2)))) Thanks for your advice. Regards, Fede