diff -r 10284ce3d5ed -r 952f9d37002c tests/hghave.py
--- a/tests/hghave.py	Tue Sep 01 18:08:24 2020 +0530
+++ b/tests/hghave.py	Thu Sep 24 16:30:00 2020 +0200
@@ -1066,6 +1066,11 @@
     )
 
 
+@check("cargo", "cargo tool")
+def has_cargo():
+    return matchoutput('`rustup which cargo` --version', b'cargo')
+
+
 @check("lzma", "python lzma module")
 def has_lzma():
     try: