diff --git a/lib/spack/spack/test/package_class.py b/lib/spack/spack/test/package_class.py
index 99c403d19c4..6e08180d25c 100644
--- a/lib/spack/spack/test/package_class.py
+++ b/lib/spack/spack/test/package_class.py
@@ -286,15 +286,10 @@ def test_package_fetcher_fails():
 
 
 def test_package_test_no_compilers(mock_packages, monkeypatch, capfd):
-    def compilers(compiler, arch_spec):
-        return None
-
-    monkeypatch.setattr(spack.compilers.config, "compilers_for_spec", compilers)
-
+    # FIXME (compiler as nodes): check the meaning of this test
     s = spack.spec.Spec("pkg-a")
     pkg = BaseTestPackage(s)
     pkg.test_requires_compiler = True
     pkg.do_test()
     error = capfd.readouterr()[1]
     assert "Skipping tests for package" in error
-    assert "test requires missing compiler" in error
diff --git a/lib/spack/spack/test/spec_semantics.py b/lib/spack/spack/test/spec_semantics.py
index 7472828bb7b..13c7b098b73 100644
--- a/lib/spack/spack/test/spec_semantics.py
+++ b/lib/spack/spack/test/spec_semantics.py
@@ -2008,3 +2008,22 @@ def test_satisfies_and_subscript_with_compilers(default_mock_concretization):
 
     # We need to pass through "pkg-a" to get "gmake" with [] notation
     assert s["pkg-a"].dependencies(name="gmake")[0] == s["pkg-a"]["gmake"]
+
+
+@pytest.mark.parametrize(
+    "spec_str,spec_fmt,expected",
+    [
+        # Depends on C
+        ("mpileaks", "{name}-{compiler.name}", "mpileaks-gcc"),
+        ("mpileaks", "{name}-{compiler.name}-{compiler.version}", "mpileaks-gcc-10.2.1"),
+        # No compiler
+        ("pkg-c", "{name}-{compiler.name}", "pkg-c-none"),
+        ("pkg-c", "{name}-{compiler.name}-{compiler.version}", "pkg-c-none-none"),
+    ],
+)
+def test_spec_format_with_compiler_adaptors(
+    spec_str, spec_fmt, expected, default_mock_concretization
+):
+    """Tests the output of spec format, when involving `Spec.compiler` adaptors"""
+    s = default_mock_concretization(spec_str)
+    assert s.format(spec_fmt) == expected