In previous tickets we have moved sage-the-distribution scripts out of src/bin.

Some scripts that are (correctly) located in src/bin use sage-system-python, which is in build/bin and not installed and not available in distributions.

src/bin/sage-coverage:1:#!/usr/bin/env sage-system-python
src/bin/sage-pypkg-location:1:#!/usr/bin/env sage-system-python
src/bin/sage-coverageall:1:#!/usr/bin/env sage-system-python
src/bin/sage-num-threads.py:1:#!/usr/bin/env sage-system-python

We change sage-coverage* to just use python3. If Sage's venv is in the front of the PATH, this is Sage's python. But these scripts work with "any python3", it does not have to be the one in which sage is installed.

We remove src/bin/sage-pypkg-location, which is undocumented and unused.

We move src/bin/sage-num-threads.py to build/bin/sage-build-num-threads (where it keeps using sage-system-python), leaving a much simplified version src/bin/sage-num-threads.py (which is using python3) behind.

CC: @dimpase @jhpalmieri @kiwifb @orlitzky @vbraun

Component: scripts

Author: Matthias Koeppe

Branch/Commit: u/mkoeppe/sagelib_s_scripts_in_src_bin_should_not_use_build_bin_sage_system_python__remove_sage_pypkg_location @ a4e757e

Reviewer: Dima Pasechnik, Sébastien Labbé

Issue created by migration from https://trac.sagemath.org/ticket/29355