ci-test: do not try to use a cache directory (huggingface#292)

* ci-test: do not try to use a cache directory

The CI tests should be stateless anyway.

* skip error code 5

* Add comment about special handing of exit code 5

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Co-authored-by: medmekk <mohamed.mekkouri@huggingface.co>

Author: danieldk

builder/lib/build.nix

@@ -320,7 +320,8 @@ rec {
               if [ -d ${extension.src}/tests ]; then
                 unset LD_LIBRARY_PATH
                 export PYTHONPATH=${extension}/${extension.variant}
-                ${testPython}/bin/python3 -m pytest ${extension.src}/tests -m kernels_ci
+                # Accept exit code 5: no tests are selected
+                ${testPython}/bin/python3 -m pytest ${extension.src}/tests -m kernels_ci -p no:cacheprovider || test $? -eq 5
               fi
             '';
         };