coerce the provides key when fingerprinting targets

src/python/pants/engine/legacy/structs.py

@@ -39,6 +39,8 @@ def _coerce_key_values(self, key, value):
       return (key, tuple(
         str(req) for req in value
       ))
+    if key == 'provides':
+      return (key, repr(value))
     return (key, value)
 
   def get_sources(self):

src/python/pants/rules/core/list_targets.py

@@ -72,8 +72,8 @@ def print_documented(target):
       print_fn = print_documented
     else:
       assert with_fingerprints
-      # To get fingerprints of each target and its dependencies, we need transitive hydrated
-      # targets.
+      # To get fingerprints of each target and its dependencies, we have to request that information
+      # specifically.
       collection = yield Get(FingerprintedTargetCollection, Specs, specs)
 
       def print_fingerprinted(fingerprinted_target):

tests/python/pants_test/backend/graph_info/tasks/test_list_targets.py

@@ -1,6 +1,7 @@
 # Copyright 2014 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
+import json
 import os
 from textwrap import dedent
 
@@ -178,3 +179,11 @@ def test_list_documented(self):
       '  Further description.',
       args=['--documented', '::'],
     )
+
+  def test_list_with_fingerprints(self):
+    self.assert_console_output_ordered(
+      json.dumps({"was_root": True, "address": "f:alias", "intransitive": "77e220c58aa54b51c7321115b21cd6e4781939b4", "transitive": "2ecd51bf9eb89dd7fb50e0563015f46a40df798f"}),
+      json.dumps({"was_root": False, "address": "a/b/c:c3", "intransitive": "2e36109fb3a97737513744edc85c03d8b7845e8f", "transitive": "97d170e1550eee4afc0af065b78cda302a97674c"}),
+      json.dumps({"was_root": False, "address": "a/b/d:d", "intransitive": "eb212be02154e79f8936fce7e9a6f31d0ddd39ff", "transitive": "97d170e1550eee4afc0af065b78cda302a97674c"}),
+      args=['--with-fingerprints', 'f:alias'],
+    )