Include package name in a freeze warning if package is not installed

news/13D1F422-0CB9-450F-B4DD-9486524712E5.feature

@@ -0,0 +1 @@
+Include the package name in a freeze warning if the package is not installed.

src/pip/_internal/operations/freeze.py

@@ -114,10 +114,10 @@ def freeze(
                         # but has been processed already
                         if not req_files[line_req.name]:
                             logger.warning(
-                                "Requirement file [%s] contains %s, but that "
-                                "package is not installed",
+                                "Requirement file [%s] contains %s, but "
+                                "package %r is not installed",
                                 req_file_path,
-                                COMMENT_RE.sub('', line).strip(),
+                                COMMENT_RE.sub('', line).strip(), line_req.name
                             )
                         else:
                             req_files[line_req.name].append(req_file_path)

tests/functional/test_freeze.py

@@ -8,7 +8,7 @@
 
 from tests.lib import (
     _create_test_package, _create_test_package_with_srcdir, need_bzr,
-    need_mercurial,
+    need_mercurial, path_to_url,
 )
 
 distribute_re = re.compile('^distribute==[0-9.]+\n', re.MULTILINE)
@@ -419,6 +419,26 @@ def test_freeze_bazaar_clone(script, tmpdir):
 """)
 
 
+def test_freeze_with_requirement_option_file_url_egg_not_installed(script):
+    """
+    Test "freeze -r requirements.txt" with a local file URL whose egg name
+    is not installed.
+    """
+
+    url = path_to_url('my-package.tar.gz') + '#egg=Does.Not-Exist'
+    requirements_path = script.scratch_path.join('requirements.txt')
+    requirements_path.write(url + '\n')
+
+    result = script.pip(
+        'freeze', '--requirement', 'requirements.txt', expect_stderr=True,
+    )
+    expected_err = (
+        'Requirement file [requirements.txt] contains {}, but package '
+        "'Does.Not-Exist' is not installed\n"
+    ).format(url)
+    assert result.stderr == expected_err
+
+
 def test_freeze_with_requirement_option(script):
     """
     Test that new requirements are created correctly with --requirement hints
@@ -444,8 +464,8 @@ def test_freeze_with_requirement_option(script):
     expected += "## The following requirements were added by pip freeze:..."
     _check_output(result.stdout, expected)
     assert (
-        "Requirement file [hint.txt] contains NoExist==4.2, but that package "
-        "is not installed"
+        "Requirement file [hint.txt] contains NoExist==4.2, but package "
+        "'NoExist' is not installed"
     ) in result.stderr
 
 
@@ -486,12 +506,12 @@ def test_freeze_with_requirement_option_multiple(script):
     """)
     _check_output(result.stdout, expected)
     assert (
-        "Requirement file [hint1.txt] contains NoExist==4.2, but that "
-        "package is not installed"
+        "Requirement file [hint1.txt] contains NoExist==4.2, but package "
+        "'NoExist' is not installed"
     ) in result.stderr
     assert (
-        "Requirement file [hint2.txt] contains NoExist2==2.0, but that "
-        "package is not installed"
+        "Requirement file [hint2.txt] contains NoExist2==2.0, but package "
+        "'NoExist2' is not installed"
     ) in result.stderr
     # any options like '--index-url http://ignore' should only be emitted once
     # even if they are listed in multiple requirements files
@@ -524,7 +544,7 @@ def test_freeze_with_requirement_option_package_repeated_one_file(script):
     """)
     _check_output(result.stdout, expected_out)
     err1 = ("Requirement file [hint1.txt] contains NoExist, "
-            "but that package is not installed\n")
+            "but package 'NoExist' is not installed\n")
     err2 = "Requirement simple2 included multiple times [hint1.txt]\n"
     assert err1 in result.stderr
     assert err2 in result.stderr
@@ -560,8 +580,8 @@ def test_freeze_with_requirement_option_package_repeated_multi_file(script):
     """)
     _check_output(result.stdout, expected_out)
 
-    err1 = ("Requirement file [hint2.txt] contains NoExist, but that "
-            "package is not installed\n")
+    err1 = ("Requirement file [hint2.txt] contains NoExist, but package "
+            "'NoExist' is not installed\n")
     err2 = ("Requirement simple included multiple times "
             "[hint1.txt, hint2.txt]\n")
     assert err1 in result.stderr