From fa3c91db7a91e03744cd0ca51b6cb8bab2e68e21 Mon Sep 17 00:00:00 2001
From: ZoeLeibowitz <zoeleibowitz12@gmail.com>
Date: Thu, 18 Jul 2024 12:45:43 +0100
Subject: [PATCH] Remove ValueError

---
 devito/petsc/utils.py | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/devito/petsc/utils.py b/devito/petsc/utils.py
index 685d7b7d58..7f300afcd5 100644
--- a/devito/petsc/utils.py
+++ b/devito/petsc/utils.py
@@ -24,10 +24,7 @@ def get_petsc_dir():
         petsc_dir = os.environ.get(i)
         if petsc_dir:
             return petsc_dir
-    raise ValueError(
-        'Environment variable PETSC_DIR is not set. '
-        'Set it to the PETSc directory.'
-    )
+    return None
 
 
 @memoized_func
@@ -37,10 +34,7 @@ def get_petsc_arch():
         petsc_arch = os.environ.get(i)
         if petsc_arch:
             return petsc_arch
-    raise ValueError(
-        'Environment variable PETSC_ARCH is not set. '
-        'Set it to the configuration of PETSc you wish to use.'
-    )
+    return None
 
 
 def core_metadata():