Currently, we "implicitly" install the local 'qemu' python package for
'make check-venv' with some logic inside tests/Makefile.include. I would
like to make this installation explicit in pythondeps.toml instead.

The version constraint specification that Python specifies does not
support relative paths, so it is difficult (or impossible?) to specify a
path within the source tree, and we will need a workaround to do so.

By specifying a package name that starts with $SRCROOT, you can now
specify a file path to a local package for installation. This is done to
allow us to install the python packages hosted inside of the tree while
also processing dependencies; i.e. so that our "qemu" package can
specify that it needs "qemu.qmp", which soon will not be included in
qemu.git.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 python/scripts/mkvenv.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/python/scripts/mkvenv.py b/python/scripts/mkvenv.py
index a22e3ee3394..e38292b63a6 100644
--- a/python/scripts/mkvenv.py
+++ b/python/scripts/mkvenv.py
@@ -736,6 +736,10 @@ def _do_ensure(
     present = []
     canary = None
     for name, info in group.items():
+        if name.startswith("$SRCROOT/"):
+            srcroot = Path(__file__).parents[2]
+            absent.append(name.replace("$SRCROOT/", f"file:///{srcroot}/"))
+            continue
         constraint = _make_version_constraint(info, False)
         matcher = Matcher(name + constraint)
         print(f"mkvenv: checking for {matcher}", file=sys.stderr)
-- 
2.51.1