At dpkg postinst, ask for reboot instead of killing desktop

.bazelrc

@@ -1,2 +1,2 @@
 build --host_cxxopt=-std=c++17
-run --workspace_status_command="bash tools/workspace-status.sh"
+build --workspace_status_command="bash tools/workspace-status.sh"

.github/workflows/master.yaml

@@ -192,7 +192,7 @@
             },
             {
                "name": "linux_amd64: build bb_clientd.deb",
-               "run": "bazel build --platforms=@rules_go//go/toolchain:linux_amd64 //:bb_clientd_deb"
+               "run": "bazel build --stamp --platforms=@rules_go//go/toolchain:linux_amd64 //:bb_clientd_deb"
             },
             {
                "name": "linux_amd64: copy bb_clientd.deb",

BUILD.bazel

@@ -1,3 +1,4 @@
+load("@aspect_bazel_lib//lib:expand_template.bzl", "expand_template")
 load("@gazelle//:def.bzl", "gazelle")
 load("@rules_pkg//:pkg.bzl", "pkg_deb", "pkg_tar")
 
@@ -35,15 +36,30 @@ pkg_tar(
     },
 )
 
+# When built with --stamp, creates a non-deterministic output file for pushing images to a remote registry.
+# With --nostamp, produces a deterministic output so dependents get cache hits.
+expand_template(
+    name = "deb_version_file",
+    out = "_deb_version.txt",
+    stamp_substitutions = {"_TAG_": "{{BUILD_SCM_TIMESTAMP}}-{{BUILD_SCM_REVISION}}"},
+    substitutions = {"_TAG_": "0~unknown"},
+    template = ["_TAG_"],
+    visibility = ["//visibility:public"],
+)
+
 pkg_deb(
     name = "bb_clientd_deb",
-    architecture = "amd64",
+    architecture = select({
+        "@platforms//cpu:x86_64": "amd64",
+        "//conditions:default": "unknown",
+    }),
     data = ":bb_clientd_deb_data",
     depends = ["fuse"],
     description = "The Buildbarn client daemon",
     homepage = "https://github.com/buildbarn/bb-clientd",
     maintainer = "The Buildbarn team",
     package = "bb-clientd",
+    package_file_name = "bb-clientd.deb",
     postinst = "configs/linux/postinst.sh",
-    version = "0.0.0",
+    version_file = ":deb_version_file",
 )

MODULE.bazel

@@ -1,11 +1,13 @@
 module(name = "com_github_buildbarn_bb_clientd")
 
+bazel_dep(name = "aspect_bazel_lib", version = "2.14.0")
 bazel_dep(name = "bazel_remote_apis", version = "0.0.0")
 bazel_dep(name = "com_github_buildbarn_bb_remote_execution")
 bazel_dep(name = "com_github_buildbarn_bb_storage")
 bazel_dep(name = "com_github_buildbarn_go_xdr")
 bazel_dep(name = "gazelle", version = "0.42.0")
 bazel_dep(name = "jsonnet_go", version = "0.20.0")
+bazel_dep(name = "platforms", version = "0.0.11")
 bazel_dep(name = "protobuf", version = "29.3")
 bazel_dep(name = "rules_jsonnet", version = "0.6.0")
 bazel_dep(name = "rules_go", version = "0.53.0")

configs/linux/postinst.sh

@@ -7,7 +7,27 @@ if ! grep -q '^user_allow_other$' /etc/fuse.conf; then
 fi
 
 # Pick up changes to /etc/logind.conf.
-systemctl restart systemd-logind.service
+if [ -z "$(loginctl --no-legend list-sessions)" ]; then
+  systemctl restart systemd-logind.service
+else
+  # Restarting systemd-logind.service effectively kills user sessions and the
+  # users' desktop environment, so let the user get a hint about reboot
+  # instead.
+  if [ "$#" -ge 2 ] && [ "$1" = "configure" ]; then
+    old_version=$2
+  else
+    old_version=""
+  fi
+  # In the future, the old version can determine if reboot is required:
+  # if dpkg --compare-versions "$old_version" lt "20250312T094712Z-2b641c6"; then
+  if [ -z "$old_version" ]; then
+    /usr/share/update-notifier/notify-reboot-required
+    if [ -e /var/run/reboot-required ]; then
+      cat /var/run/reboot-required
+    fi
+    echo "Please reboot to apply changes to /etc/logind.conf"
+  fi
+fi
 
 # Pick up changes to the systemd service.
 systemctl daemon-reload

tools/github_workflows/github_workflows.jsonnet

@@ -12,7 +12,7 @@ workflows_template.getWorkflows(
         steps+: [
           {
             name: 'linux_amd64: build bb_clientd.deb',
-            run: 'bazel build --platforms=@rules_go//go/toolchain:linux_amd64 //:bb_clientd_deb',
+            run: 'bazel build --stamp --platforms=@rules_go//go/toolchain:linux_amd64 //:bb_clientd_deb',
           },
           {
             name: 'linux_amd64: copy bb_clientd.deb',