From 1ea8230d264d354640e6bd16bedff4850181e7c8 2020-06-02 22:49:38
From: Matthias Bussonnier <bussonniermatthias@gmail.com>
Date: 2020-06-02 22:49:38
Subject: [PATCH] Merge pull request #12361 from meeseeksmachine/auto-backport-of-pr-12360-on-7.x

Backport PR #12360 on branch 7.x (use $SHELL in system_piped)
---

diff --git a/IPython/utils/_process_posix.py b/IPython/utils/_process_posix.py
index f3f93f7..a11cad7 100644
--- a/IPython/utils/_process_posix.py
+++ b/IPython/utils/_process_posix.py
@@ -59,11 +59,12 @@ class ProcessHandler(object):
 
     @property
     def sh(self):
-        if self._sh is None:        
-            self._sh = pexpect.which('sh')
+        if self._sh is None:
+            shell_name = os.environ.get("SHELL", "sh")
+            self._sh = pexpect.which(shell_name)
             if self._sh is None:
-                raise OSError('"sh" shell not found')
-        
+                raise OSError('"{}" shell not found'.format(shell_name))
+
         return self._sh
 
     def __init__(self, logfile=None, read_timeout=None, terminate_timeout=None):