- Make a fresh clone of a 3.0.2 build.
- touch $SAGE_ROOT/devel/sage-test1/sage/libs/mwrank/mwrank.pyx
- sage -b
- touch $SAGE_ROOT/devel/sage-test1/sage/libs/mwrank/wrap.cc
- sage -b
...produces this:
----------------------------------------------------------
sage: Building and installing modified SAGE library files.
Installing c_lib
scons: `install' is up to date.
running install
running build
running build_py
running build_ext
building 'sage.libs.mwrank.mwrank' extension
error: unknown file type '.pyx' (from 'sage/libs/mwrank/mwrank.pyx')
sage: There was an error installing modified sage library code.
but then after doing again
touch $SAGE_ROOT/devel/sage-test1/sage/libs/mwrank/mwrank.pyx
sage -br works fine.