Revert "tests: Use separate virtual environment for avocado"

This reverts commit e8e4298feadae7924cf7600bb3bcc5b0a8d7cbe9.

ensuregroup allows to specify both the acceptable versions of avocado,
and a locked version to be used when avocado is not installed as a system
pacakge.  This lets us install avocado in pyvenv/ using "mkvenv.py" and
reuse the distro package on Fedora and CentOS Stream (the only distros
where it's available).

ensuregroup's usage of "(>=..., <=...)" constraints when evaluating
the distro package, and "==" constraints when installing it from PyPI,
makes it possible to avoid conflicts between the known-good version and
a package plugins included in the distro.

This is because package plugins have "==" constraints on the version
that is included in the distro, and, using "pip install avocado==88.1"
on a venv that includes system packages will result in an error:

   avocado-framework-plugin-varianter-yaml-to-mux 98.0 requires avocado-framework==98.0, but you have avocado-framework 88.1 which is incompatible.
   avocado-framework-plugin-result-html 98.0 requires avocado-framework==98.0, but you have avocado-framework 88.1 which is incompatible.

But at the same time, if the venv does not include a system distribution
of avocado then we can install a known-good version and stick to LTS
releases.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1663
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/python/scripts/mkvenv.py b/python/scripts/mkvenv.py
index 02bcd9a8c9..4f2349fbb6 100644
--- a/python/scripts/mkvenv.py
+++ b/python/scripts/mkvenv.py
@@ -964,14 +964,11 @@ def _parse_groups(file: str) -> Dict[str, Dict[str, Any]]:
             "Python >=3.11 does not have tomllib... what have you done!?"
         )
 
-    try:
-        # Use loads() to support both tomli v1.2.x (Ubuntu 22.04,
-        # Debian bullseye-backports) and v2.0.x
-        with open(file, "r", encoding="ascii") as depfile:
-            contents = depfile.read()
-            return tomllib.loads(contents)  # type: ignore
-    except tomllib.TOMLDecodeError as exc:
-        raise Ouch(f"parsing {file} failed: {exc}") from exc
+    # Use loads() to support both tomli v1.2.x (Ubuntu 22.04,
+    # Debian bullseye-backports) and v2.0.x
+    with open(file, "r", encoding="ascii") as depfile:
+        contents = depfile.read()
+        return tomllib.loads(contents)  # type: ignore
 
 
 def ensure_group(