Report detailed information about invalid requirements

news/12713.feature.rst

@@ -0,0 +1 @@
+Report informative messages about invalid requirements.

src/pip/_internal/req/constructors.py

@@ -206,8 +206,8 @@ def parse_req_from_editable(editable_req: str) -> RequirementParts:
  if name is not None:
  try:
  req: Optional[Requirement] = Requirement(name)
- except InvalidRequirement:
- raise InstallationError(f"Invalid requirement: '{name}'")
+ except InvalidRequirement as exc:
+ raise InstallationError(f"Invalid requirement: {name!r}: {exc}")
  else:
  req = None
 
@@ -360,7 +360,7 @@ def with_source(text: str) -> str:
  def _parse_req_string(req_as_string: str) -> Requirement:
  try:
  return get_requirement(req_as_string)
- except InvalidRequirement:
+ except InvalidRequirement as exc:
  if os.path.sep in req_as_string:
  add_msg = "It looks like a path."
  add_msg += deduce_helpful_msg(req_as_string)
@@ -370,7 +370,7 @@ def _parse_req_string(req_as_string: str) -> Requirement:
  add_msg = "= is not a valid operator. Did you mean == ?"
  else:
  add_msg = ""
- msg = with_source(f"Invalid requirement: {req_as_string!r}")
+ msg = with_source(f"Invalid requirement: {req_as_string!r}: {exc}")
  if add_msg:
  msg += f"\nHint: {add_msg}"
  raise InstallationError(msg)
@@ -429,8 +429,8 @@ def install_req_from_req_string(
 ) -> InstallRequirement:
  try:
  req = get_requirement(req_string)
- except InvalidRequirement:
- raise InstallationError(f"Invalid requirement: '{req_string}'")
+ except InvalidRequirement as exc:
+ raise InstallationError(f"Invalid requirement: {req_string!r}: {exc}")
 
  domains_not_allowed = [
  PyPI.file_storage_domain,