preserve environment variables when calling pass show

bwpass.py

@@ -4,14 +4,19 @@ from subprocess import check_output, CalledProcessError
 
 from bundlewrap.exceptions import FaultUnavailable
 from bundlewrap.utils import Fault
+from bundlewrap.utils.dict import merge_dict
 from bundlewrap.utils.text import bold, yellow
 from bundlewrap.utils.ui import io
 
-PASSWORD_STORE_DIR = expanduser(environ.get('BW_PASS_DIR', '~/.password-store'))
+ENVIRONMENT = merge_dict(environ, {
+    'PASSWORD_STORE_DIR': expanduser(environ.get('BW_PASS_DIR', '~/.password-store')).
+})
+
 DUMMY_MODE = environ.get('BW_PASS_DUMMY_MODE', '0') == '1'
 
 cache = {}
 
+
 def _get_contents_from_pass(identifier: str):
     try:
         return cache[identifier]
@@ -26,9 +31,7 @@ def _get_contents_from_pass(identifier: str):
         try:
             pass_output = check_output(
                 ['pass', 'show', identifier],
-                env={
-                    'PASSWORD_STORE_DIR': PASSWORD_STORE_DIR,
-                }
+                env=ENVIRONMENT,
             ).decode('UTF-8').splitlines()
         except FileNotFoundError:
             raise FaultUnavailable('pass not found')