bazel_6: MODULE.bazel.lock file is empty

[avdv]

Describe the bug

Using Bazel from nixpkgs in a project with bzlmod enabled, and --lockfile_mode=update the generated MODULE.bazel.lock file does only contain an empty JSON object.

Steps To Reproduce

Steps to reproduce the behavior:

1. git clone https://github.com/bazelbuild/examples.git
2. cd examples/bzlmod/01-depend_on_bazel_module
3. rm .bazelversion
4. nix run nixpkgs#bazel_6 -- mod deps --lockfile_mode=update

$ nix run nixpkgs#bazel_6 version
Build label: 6.4.0- (@non-git)
Build target: bazel-out/k8-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Tue Jan 1 00:00:00 1980 (315532800)
Build timestamp: 315532800
Build timestamp as int: 315532800
$ ls -lh MODULE.bazel.lock
-rw-r--r-- 1 claudio users 3 Dec 11 09:02 MODULE.bazel.lock
$ head MODULE.bazel.lock
{}

Expected behavior

The generated lock file should be equivalent to the file generated by a vanilla Bazel distribution binary:

$ bazel version
Bazelisk version: v1.16.0
Starting local Bazel server and connecting to it...
Build label: 6.4.0
Build target: bazel-out/k8-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Thu Oct 19 17:07:43 2023 (1697735263)
Build timestamp: 1697735263
Build timestamp as int: 1697735263
$  bazel mod deps --lockfile_mode=update
<root> ([email protected])

 checking cached actions
$ ls -lh ls -lh MODULE.bazel.lock 
-rw-r--r-- 1 root root 75K Dec 11 08:07 MODULE.bazel.lock
$ head MODULE.bazel.lock
{
  "lockFileVersion": 3,
  "moduleFileHash": "47f831d13c88b71ebfb233245e6e8c208f8d2e09b51e780699178a31ccf165dd",
  "flags": {
    "cmdRegistries": [
      "https://bcr.bazel.build/"
    ],
    "cmdModuleOverrides": {},
    "allowedYankedVersions": [],
    "envVarAllowedYankedVersions": "",

Additional context

See also bazelbuild/bazel#19672 where the same problem was reported for Bazel from homebrew.

The formula from homebrew is here:
https://github.com/Homebrew/homebrew-core/blob/fda88ddb4c8ea04adcfa001c56a1b35aebd64e86/Formula/b/bazel.rb

Notify maintainers

@NixOS/bazel

Metadata

[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 6.6.1-zen1, NixOS, 23.11 (Tapir), 23.11.20231128.7c4c205`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.18.1`
 - channels(root): `"nixos-21.11.336182.a25df4c2b79"`
 - nixpkgs: `/etc/nixpkgs`

---

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[avdv]

Comparing the server.jar from an official bindist and the bazel_6 package, it is apparent that the package one is missing all the gson type adapter classes:

com/google/devtools/build/lib/bazel/bzlmod/AttributeValues_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/BazelLockFileValue_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/BzlmodFlagsAndEnvVars_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/GsonTypeAdapterUtil_RootModuleFileEscapingLocation_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/InterimModule_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/LockFileModuleExtension_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/ModuleExtensionEvalFactors_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/ModuleExtensionMetadata_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/ModuleExtensionUsage_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/Module_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/RepoSpec_GsonTypeAdapter.class
com/google/devtools/build/lib/bazel/bzlmod/Tag_GsonTypeAdapter.class

[aaronmondal]

bazelbuild/bazel#18455