expand env before run script

Signed-off-by: Frost Ming <mianghong@gmail.com>

news/3178.bugfix.rst

@@ -0,0 +1 @@
+Environment variables are expanded correctly before running scripts on POSIX.

pipenv/core.py

@@ -2262,7 +2262,7 @@ def do_run_nt(script):
 
 
 def do_run_posix(script, command):
-    command_path = system_which(script.command)
+    command_path = system_which(os.path.expandvars(script.command))
     if not command_path:
         if project.has_script(command):
             click.echo(
@@ -2287,7 +2287,9 @@ def do_run_posix(script, command):
                 err=True,
             )
         sys.exit(1)
-    os.execl(command_path, command_path, *script.args)
+    os.execl(
+        command_path, command_path, *[os.path.expandvars(arg) for arg in script.args]
+    )
 
 
 def do_run(command, args, three=None, python=False, pypi_mirror=None):

tests/integration/test_run.py

@@ -1,6 +1,7 @@
 import os
 
 from pipenv.project import Project
+from pipenv.utils import temp_environ
 
 import pytest
 
@@ -27,6 +28,7 @@ printfoo = "python -c \"print('foo')\""
 notfoundscript = "randomthingtotally"
 appendscript = "cmd arg1"
 multicommand = "bash -c \"cd docs && make html\""
+scriptwithenv = "echo $HELLO"
             """)
         c = p.pipenv('install')
         assert c.return_code == 0
@@ -52,3 +54,9 @@ multicommand = "bash -c \"cd docs && make html\""
         script = project.build_script('appendscript', ['a', 'b'])
         assert script.command == 'cmd'
         assert script.args == ['arg1', 'a', 'b']
+
+        with temp_environ():
+            os.environ['HELLO'] = 'WORLD'
+            c = p.pipenv("run scriptwithenv")
+            assert c.ok
+            assert c.out.strip() == "WORLD"