GODRIVER-3989 Add a drivers-evergreen-tools submodule with a pinned revision.

.evergreen/setup-system.sh

@@ -45,9 +45,13 @@ else
     CURRENT_VERSION=latest
 fi
 
-# Ensure a checkout of drivers-tools.
+# If $DRIVERS_TOOLS doesn't already exist, clone it using the pinned revision of
+# the drivers-evergreen-tools submodule. We clone a copy here because modifying
+# the submodule directory directly doesn't work on Windows for some reason.
 if [ ! -d "$DRIVERS_TOOLS" ]; then
+  detrev=$(git ls-tree --object-only HEAD .evergreen/drivers-evergreen-tools)
   git clone https://github.com/mongodb-labs/drivers-evergreen-tools $DRIVERS_TOOLS
+  git -C $DRIVERS_TOOLS checkout $detrev
 fi
 
 # Write the .env file for drivers-tools.

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "specifications"]
 	path = testdata/specifications
 	url = https://github.com/mongodb/specifications
+[submodule ".evergreen/drivers-evergreen-tools"]
+	path = .evergreen/drivers-evergreen-tools
+	url = https://github.com/mongodb-labs/drivers-evergreen-tools.git

etc/check_license.sh

@@ -61,8 +61,10 @@ FILES=$1
 
 # If no filenames were passed, find all .go files and try to write a license
 # notice.
+#
+# Ignore "hidden" directories that start with a "."
 if [ -z "$FILES" ]; then
-    FILES=$(find . -type f -name "*.go" -print)
+    FILES=$(find . -path '*/.*' -prune -o -type f -name "*.go" -print)
 fi
 
 for file in $FILES

go.mod

@@ -19,3 +19,8 @@ require (
 )
 
 replace golang.org/x/net/http2 => golang.org/x/net/http2 v0.23.0 // GODRIVER-3225
+
+// Ignore the .evergreen directory so that Go modules contained in the
+// .evergreen/drivers-evergreen-tools submodule are not included in Go commands
+// and not formatted with gofumpt.
+ignore ./.evergreen