Fix constraint validation

news/4386.bugfix.rst

@@ -0,0 +1 @@
+Fix a bug that non-wheel file requirements can be resolved successfully.

pipenv/cli/options.py

@@ -440,6 +440,7 @@ def lock_options(f):
     f = install_base_options(f)
     f = lock_dev_option(f)
     f = emit_requirements_flag(f)
+    f = emit_requirements_header_flag(f)
     f = dev_only_flag(f)
     return f
 

pipenv/core.py

@@ -841,15 +841,15 @@ def do_install_dependencies(
     dev = dev or dev_only
     deps_list = list(lockfile.get_requirements(dev=dev, only=dev_only))
     if emit_requirements:
-        index_args = prepare_pip_source_args(get_source_list(pypi_mirror=pypi_mirror, project=project))
+        index_args = prepare_pip_source_args(
+            get_source_list(pypi_mirror=pypi_mirror, project=project)
+        )
         index_args = " ".join(index_args).replace(" -", "\n-")
         deps = [
             req.as_line(sources=False, include_hashes=False) for req in deps_list
         ]
         click.echo(index_args)
-        click.echo(
-            "\n".join(sorted(deps))
-        )
+        click.echo("\n".join(sorted(deps)))
         sys.exit(0)
     if concurrent:
         nprocs = PIPENV_MAX_SUBPROCESS

pipenv/resolver.py

@@ -562,13 +562,15 @@ class Entry(object):
         :return: True if the constraints are satisfied by the resolution provided
         :raises: :exc:`pipenv.exceptions.DependencyConflict` if the constraints dont exist
         """
+        from pipenv.exceptions import DependencyConflict
+        from pipenv.environments import is_verbose
+
         constraints = self.get_constraints()
+        old_version = self.strip_version(self.old_specifiers)
         for constraint in constraints:
-            try:
-                constraint.check_if_exists(False)
-            except Exception:
-                from pipenv.exceptions import DependencyConflict
-                from pipenv.environments import is_verbose
+            if not constraint.req:
+                continue
+            if not constraint.req.specifier.contains(str(old_version), prereleases=True):
                 if is_verbose():
                     print("Tried constraint: {0!r}".format(constraint), file=sys.stderr)
                 msg = (