New comment by Johnnynator on void-packages repository

https://github.com/void-linux/void-packages/pull/27364#issuecomment-752986951

Comment:
They fail because `errno` on Musl and Glibc expand differently by one space.
```
xml.sw:
--- xml.sw.approved.txt

+++ xml.sw.unapproved.txt

-          errno == 1
+          (*__errno_location()) == 1
  
****************************
  Results differed
```

Can you add this patch and remove your `|| msg_warn`
```patch
--- scripts/approvalTests.py	2019-12-28 21:24:04.000000000 +0100
+++ -	2020-12-31 16:19:56.118506507 +0100
@@ -44,7 +44,7 @@
 
 # errno macro expands into various names depending on platform, so we need to fix them up as well
 errnoParser = re.compile(r'''
-    \(\*__errno_location\ \(\)\)
+    \(\*__errno_location\s*\(\)\)
     |
     \(\*__error\(\)\)
     |

```
https://github.com/catchorg/Catch2/pull/2143