tests: invoke run-tests.py in test-hghave using $PYTHON (
issue5697)
Some platforms (notably pkgsrc on NetBSD) only provide versioned
Python interpreters (eg `python2.7` exists, but `python` does not),
which exposes this error. We want to be running run-tests.py with the
python given in $PYTHON, since that might be `pypy` or `python3`.
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present