crate_universe: Enable modext isolation.

This should allow us to build our python and ruby
code independently - in particular, we can now do shallow
checkouts of one without the other.
Previously, the modext introduced cross-dependency.
This also reduces the amount of work we do in the
crate universe processing for the other language, even
though it's unused.

This does need renaming the module, as otherwise
the generated paths from rules_rust get too long
for Windows :(

.bazelrc

@@ -24,5 +24,6 @@ common --registry=file:///%workspace%/misc/bazel/registry
 common --registry=https://bcr.bazel.build
 
 common --@rules_dotnet//dotnet/settings:strict_deps=false
+common --experimental_isolated_extension_usages
 
 try-import %workspace%/local.bazelrc

.bazelrc.internal

@@ -8,3 +8,4 @@ common --registry=https://bcr.bazel.build
 # its implementation packages without providing any code itself.
 # We either can depend on internal implementation details, or turn of strict deps.
 common --@rules_dotnet//dotnet/settings:strict_deps=false
+common --experimental_isolated_extension_usages

MODULE.bazel

@@ -1,6 +1,7 @@
 module(
-    name = "codeql",
+    name = "ql",
     version = "0.0",
+    repo_name = "codeql",
 )
 
 # this points to our internal repository when `codeql` is checked out as a submodule thereof
@@ -30,27 +31,37 @@ bazel_dep(name = "rules_rust", version = "0.49.1")
 
 bazel_dep(name = "buildifier_prebuilt", version = "6.4.0", dev_dependency = True)
 
-crate = use_extension(
+# crate_py but shortened due to Windows file path considerations
+cp = use_extension(
     "@rules_rust//crate_universe:extension.bzl",
     "crate",
+    isolate = True,
 )
-crate.from_cargo(
+cp.from_cargo(
     name = "py_deps",
     cargo_lockfile = "//python/extractor/tsg-python:Cargo.lock",
     manifests = [
         "//python/extractor/tsg-python:Cargo.toml",
         "//python/extractor/tsg-python/tsp:Cargo.toml",
     ],
 )
-crate.from_cargo(
-    name = "ruby_deps",
+use_repo(cp, "py_deps")
+
+# crate_ruby, but shortened due to windows file paths
+r = use_extension(
+    "@rules_rust//crate_universe:extension.bzl",
+    "crate",
+    isolate = True,
+)
+r.from_cargo(
+    name = "rd",
     cargo_lockfile = "//ruby/extractor:Cargo.lock",
     manifests = [
         "//ruby/extractor:Cargo.toml",
         "//ruby/extractor/codeql-extractor-fake-crate:Cargo.toml",
     ],
 )
-use_repo(crate, "py_deps", "ruby_deps")
+use_repo(r, "rd")
 
 dotnet = use_extension("@rules_dotnet//dotnet:extensions.bzl", "dotnet")
 dotnet.toolchain(dotnet_version = "8.0.101")

misc/bazel/internal/zipmerge/zipmerge_test.cpp

@@ -75,7 +75,7 @@ std::string get_file(const char* name) {
     return ret;
   }();
   // this works from both `codeql` and the internal repository
-  for (auto prefix : {"_main", "codeql~"}) {
+  for (auto prefix : {"_main", "ql~"}) {
     auto ret = runfiles->Rlocation(prefix + "/misc/bazel/internal/zipmerge/test-files/"s + name);
     if (fs::exists(ret)) {
       return ret;

ruby/extractor/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@ruby_deps//:defs.bzl", "aliases", "all_crate_deps")
+load("@rd//:defs.bzl", "aliases", "all_crate_deps")
 load("//misc/bazel:rust.bzl", "codeql_rust_binary")
 
 codeql_rust_binary(

shared/tree-sitter-extractor/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@ruby_deps//:defs.bzl", "aliases", "all_crate_deps")
+load("@rd//:defs.bzl", "aliases", "all_crate_deps")
 load("@rules_rust//rust:defs.bzl", "rust_library")
 
 package(default_visibility = ["//visibility:public"])