fix: catch errors in remote.AUTO provider list

snakemake/remote/__init__.py

@@ -471,10 +471,14 @@ def protocol_mapping(self):
         # assemble scheme mapping
         protocol_dict = {}
         for Provider in provider_list:
-            for protocol in Provider().available_protocols:
-                protocol_short = protocol[:-3]  # remove "://" suffix
-                protocol_dict[protocol_short] = Provider
-
+            try:
+                for protocol in Provider().available_protocols:
+                    protocol_short = protocol[:-3]  # remove "://" suffix
+                    protocol_dict[protocol_short] = Provider
+            except Exception as e:
+                # If for any reason Provider() fails (e.g. missing python
+                # packages or config env vars), skip this provider.
+                logger.debug(f"Instantiating {Provider.__class__.__name__} failed: {e}")
         return protocol_dict
 
     def remote(self, value, *args, provider_kws=None, **kwargs):

tests/test_remote_auto/Snakefile

@@ -0,0 +1,10 @@
+#import re, os, sys
+shell.executable("bash")
+
+from snakemake.remote import AUTO
+
+rule all:
+    input:
+        AUTO.remote("https://github.com/snakemake/snakemake/raw/main/images/logo.png")
+    run:
+        shell("cp {input} ./")