diff --git a/.github/workflows/unit_tests.yaml b/.github/workflows/unit_tests.yaml
index 6d5901edd1..726c56e617 100644
--- a/.github/workflows/unit_tests.yaml
+++ b/.github/workflows/unit_tests.yaml
@@ -156,6 +156,8 @@ jobs:
           make -C ${KCOV_ROOT}/build && sudo  make -C ${KCOV_ROOT}/build install
     - name: Bootstrap clingo from sources
       if: ${{ matrix.concretizer == 'clingo' }}
+      env:
+          SPACK_PYTHON: python
       run: |
           . share/spack/setup-env.sh
           spack external find --not-buildable cmake bison
@@ -163,6 +165,7 @@ jobs:
     - name: Run unit tests (full suite with coverage)
       if: ${{ needs.changes.outputs.with_coverage == 'true' }}
       env:
+          SPACK_PYTHON: python
           COVERAGE: true
           SPACK_TEST_SOLVER: ${{ matrix.concretizer }}
       run: |
@@ -172,6 +175,7 @@ jobs:
     - name: Run unit tests (reduced suite without coverage)
       if: ${{ needs.changes.outputs.with_coverage == 'false' }}
       env:
+          SPACK_PYTHON: python
           ONLY_PACKAGES: true
           SPACK_TEST_SOLVER: ${{ matrix.concretizer }}
       run: |
diff --git a/lib/spack/spack/test/conftest.py b/lib/spack/spack/test/conftest.py
index 8d0ff77bb9..2443d0edf0 100644
--- a/lib/spack/spack/test/conftest.py
+++ b/lib/spack/spack/test/conftest.py
@@ -12,20 +12,19 @@
 import os.path
 import re
 import shutil
-import sys
 import tempfile
 import xml.etree.ElementTree
 
-if sys.version_info >= (3,):
+try:
     # CVS outputs dates in different formats on different systems. We are using
     # the dateutil package to parse these dates. This package does not exist
-    # for Python 2.x. That means that we cannot test checkouts "by date" for
+    # for Python <2.7. That means that we cannot test checkouts "by date" for
     # CVS respositories. (We can still use CVS repos with all features, only
     # our tests break.)
     from dateutil.parser import parse as parse_date
-else:
-    def parse_date(string):
-        pytest.skip("dateutil package not available for Python 2.6")
+except ImportError:
+    def parse_date(string):  # type: ignore
+        pytest.skip("dateutil package not available")
 
 import py
 import pytest