SageNB broken when SAGE_PATH contains flavours of '.' during installation

[hivert]

When SAGE_PATH (and hence also PYTHONPATH) contains "." (the current working directory) during the installation of sagenb, Python is able to find sagenb in its path and therefore refuses to add it to easy-install.pth. Later, Sage won't find it, leading to the following error message:

ImportError: No module named sagenb.misc.sphinxify
Error importing ipy_profile_sage - perhaps you should run %upgrade?
WARNING: Loading of ipy_profile_sage failed.

This is a follow-up to #10176, and there has been some discussion on sage-release.

---

Apply only

attachment: 10192-remove_dot_from_PYTHONPATH_in_sage-spkg.2.patch
to the Sage root repository.

Depends on #11073

CC: @nexttime @qed777 @mwhansen @jdemeyer @jhpalmieri

Component: build

Keywords: notebook installation dot PYTHONPATH easy_install easy-install pth sage-spkg setuptools

Author: Leif Leonhardy, Punarbasu Purkayastha

Reviewer: Florent Hivert, Jeroen Demeyer

Merged: sage-5.0.beta6

Issue created by migration from https://trac.sagemath.org/ticket/10192

[nexttime]

Changed keywords from notebook installation to notebook installation dot PYTHONPATH easy_install easy-install pth sage-spkg setuptools

[nexttime]

comment:2

From sage-env:

if [ -d "$SAGE_ROOT/local/lib/python" ]; then
    PYTHONPATH="$SAGE_PATH:$SAGE_ROOT/local/lib/python"   && export PYTHONPATH
    PYTHONHOME="$SAGE_ROOT/local" && export PYTHONHOME
fi

We shouldn't add $SAGE_PATH there if it is empty btw., but the removal of "." from PYTHONPATH should be performed in sage-spkg I think.

($SAGE_PATH is also appended to an overwritten(?!) PYTHONPATH in sage-doctest.)

[nexttime]

Author: Leif Leonhardy

[nexttime]

comment:3

Ok, after changing some instances of PYTHON_PATH to PYTHONPATH (argh!), the attached patch works for me.

You can try setting SAGE_PATH to something containing "." (e.g. ":/foo/bar:.:/baz, too), of course also doing export SAGE_PATH, then [re]installing the SageNB 0.8.7 spkg (or the newer ones, p1 or p2, but these aren't necessary, i.e., the patch here fixes the issue in a different way, not needing an additional work-around).

[nexttime]

comment:4

As far as I know, Cygwin (as opposed to MS DOS/Windows) also uses ":" to separate directories in search paths, so this should work for Cygwin as well.

(Other shell and even Python scripts in Sage also hard-code that character.)

[hivert]

Reviewer: Florent Hivert