[bitbake-devel] [PATCH master 1.42] fetch2: runfetchcmd(): unset _PYTHON_SYSCONFIGDATA_NAME

[Matthias Schiffer]

Since warrior, python3native.bbclass sets _PYTHON_SYSCONFIGDATA_NAME;
unfortunately, this also affects Python scripts run as fetch commands like
git-make-shallow, breaking it with a message like

    Failed to import the site module
    Traceback (most recent call last):
      File "/usr/lib/python3.6/site.py", line 570, in <module>
        main()
      File "/usr/lib/python3.6/site.py", line 556, in main
        known_paths = addusersitepackages(known_paths)
      File "/usr/lib/python3.6/site.py", line 288, in addusersitepackages
        user_site = getusersitepackages()
      File "/usr/lib/python3.6/site.py", line 264, in getusersitepackages
        user_base = getuserbase() # this will also set USER_BASE
      File "/usr/lib/python3.6/site.py", line 254, in getuserbase
        USER_BASE = get_config_var('userbase')
      File "/usr/lib/python3.6/sysconfig.py", line 607, in get_config_var
        return get_config_vars().get(name)
      File "/usr/lib/python3.6/sysconfig.py", line 550, in get_config_vars
        _init_posix(_CONFIG_VARS)
      File "/usr/lib/python3.6/sysconfig.py", line 421, in _init_posix
        _temp = __import__(name, globals(), locals(), ['build_time_vars'], 0)
    ModuleNotFoundError: No module named '_sysconfigdata'

on an Ubuntu 18.04 system (and likely others) when building with
BB_GIT_SHALLOW and BB_GENERATE_SHALLOW_TARBALLS.

Unset _PYTHON_SYSCONFIGDATA_NAME in runfetchcmd() to work around this.

Signed-off-by: Matthias Schiffer <matthias.schiffer at ew.tq-group.com>
---

I think this (or a different fix for this issue) should be added to both
master and 1.42, as Yocto warrior is affected.

Note that this fix assumes that the host Python does not need a
_PYTHON_SYSCONFIGDATA_NAME, which should be true on most systems. A more
complete fix would be to reset _PYTHON_SYSCONFIGDATA_NAME to its original
value, but I don't know the Bitbake code well enough to do that.

 lib/bb/fetch2/__init__.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/bb/fetch2/__init__.py b/lib/bb/fetch2/__init__.py
index 0126e0d7..f6b5529b 100644
--- a/lib/bb/fetch2/__init__.py
+++ b/lib/bb/fetch2/__init__.py
@@ -843,6 +843,11 @@ def runfetchcmd(cmd, d, quiet=False, cleanup=None, log=None, workdir=None):
         if val:
             cmd = 'export ' + var + '=\"%s\"; %s' % (val, cmd)
 
+    # Ensure that a _PYTHON_SYSCONFIGDATA_NAME value set by a recipe
+    # (for example via python3native.bbclass since warrior) is not set for
+    # host Python (otherwise tools like git-make-shallow will fail)
+    cmd = 'unset _PYTHON_SYSCONFIGDATA_NAME; ' + cmd
+
     # Disable pseudo as it may affect ssh, potentially causing it to hang.
     cmd = 'export PSEUDO_DISABLED=1; ' + cmd
 
-- 
2.17.1