Fix bare 'except:' to placate errors in new flake8 version.

- fixes E722 errors from latest version of flake8
- requires us to not use 'bare except:' and catch BaseException instead

var/spack/repos/builtin/packages/hdf5-blosc/package.py

@@ -184,7 +184,7 @@ def check_install(self, spec):
             try:
                 check = Executable("./check")
                 output = check(output=str)
-            except:
+            except ProcessError:
                 output = ""
             success = output == expected
             if not success: