Add config to require licences for pip_library and python_wheel (#128)

.plzconfig

@@ -119,6 +119,13 @@ Optional = true
 Inherit = true
 Help = The tool used to resolve wheels with using the pypi API.
 
+[PluginConfig "require_licences"]
+DefaultValue = false
+Type = bool
+Inherit = true
+Help = If set, the licences field on pip_library and python_wheel will be mandatory
+
+
 [PluginConfig "feature_flags"]
 DefaultValue = ""
 Repeatable = true

build_defs/python.build_defs

@@ -760,7 +760,12 @@ def _add_licences(name, output):
             add_licence(name, line.split(' :: ')[-1])
             found = True
     if not found:
-        log.warning('No licence found for %s, should add licences = [...] to the rule', name.lstrip('_').split('#')[0])
+        name = name.lstrip('_').split('#')[0]
+        msg = f'No licence found for {name}, should add licences = [...] to the rule'
+        if CONFIG.PYTHON.REQUIRE_LICENCES:
+            fail(msg)
+        else:
+            log.warning(msg)
 
 
 # `pdb` and `debugpy` are the current debuggers supported by the PEX tool.