feat(task): discover Go workspaces

TASK_CACHE_PARITY.md

@@ -58,7 +58,7 @@ outside this tracker.
 - [x] Explain which provider inferred each project, task, input, output, and dependency
 - [x] Add Cargo workspace and path-dependency inference
 - [x] Add uv workspace and local/path-dependency inference
-- [ ] Add Go workspace discovery, with explicit dependency overrides where module metadata is
+- [x] Add Go workspace discovery, with explicit dependency overrides where module metadata is
       insufficient
 
 ## Affected project execution

docs/tasks/monorepo.md

@@ -411,6 +411,27 @@ external-workspace sources do not add projects or edges. Self-dependencies are i
 cycles among projects are reported by `mise tasks graph` and can be corrected with project
 overrides.
 
+### Go Workspace Discovery
+
+The Go provider discovers modules listed by `use` directives in the root `go.work`. Both individual
+directives and `use` blocks are supported. Each listed directory must contain a `go.mod` with a
+`module` directive; mise uses that stable module path to create an ID such as
+`go:example.com/acme/api`. Modules listed outside the configured monorepo root are ignored because
+project roots in the mise graph are always repository-relative.
+
+Discovery parses `go.work` and `go.mod` directly and does not require the `go` executable. It does
+not infer dependency edges from `require` or `replace`: those directives describe module selection,
+not necessarily the source-level relationship needed by a task graph. Add the edges that matter to
+your build with project overrides:
+
+```toml
+[monorepo.projects."go:example.com/acme/api"]
+depends_add = ["go:example.com/acme/lib"]
+```
+
+Use `depends` to replace the complete dependency set, or `depends_add` and `depends_remove` for
+targeted adjustments. The graph explanation attributes these configured edges to `configuration`.
+
 ### Node Workspace Discovery
 
 The Node provider discovers npm, pnpm, Yarn, and Bun workspace packages from:

e2e/tasks/test_task_go_workspace_graph

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+
+export MISE_EXPERIMENTAL=1
+
+cat <<'EOF' >mise.toml
+monorepo_root = true
+
+[monorepo.projects."go:example.com/acme/api"]
+depends_add = ["go:example.com/acme/lib"]
+EOF
+
+cat <<'EOF' >go.work
+go 1.25
+
+use (
+  ./cmd/api
+  ./lib
+)
+EOF
+
+mkdir -p cmd/api lib
+
+cat <<'EOF' >cmd/api/go.mod
+module example.com/acme/api
+
+go 1.25
+
+require example.com/acme/lib v0.0.0
+EOF
+
+cat <<'EOF' >lib/go.mod
+module example.com/acme/lib
+
+go 1.25
+EOF
+
+assert_contains "mise tasks graph" "go:example.com/acme/api"
+assert_contains "mise tasks graph" "cmd/api"
+assert_contains "mise tasks graph" '"workspace_source":"go.mod"'
+assert_contains "mise tasks graph --explain" "Project: go:example.com/acme/api"
+assert_contains "mise tasks graph --explain" "go:example.com/acme/lib — configuration"
+
+assert_json "mise tasks graph --json | jq '.projects | map({id, root, dependencies})'" '[
+  {
+    "id": "go:example.com/acme/api",
+    "root": "cmd/api",
+    "dependencies": [
+      "go:example.com/acme/lib"
+    ]
+  },
+  {
+    "id": "go:example.com/acme/lib",
+    "root": "lib",
+    "dependencies": []
+  }
+]'
+
+assert_json "mise tasks graph --json | jq '.projects[] | select(.id == \"go:example.com/acme/api\") | .provenance'" '{
+  "provider": "go",
+  "source": "cmd/api/go.mod"
+}'

src/config/mod.rs

@@ -506,18 +506,19 @@ impl Config {
             .cloned()
             .unwrap_or_default();
         let cargo = crate::task::workspace::cargo::CargoWorkspaceProvider;
+        let go = crate::task::workspace::go::GoWorkspaceProvider;
         let node = crate::task::workspace::node::NodeWorkspaceProvider;
         let uv = crate::task::workspace::uv::UvWorkspaceProvider;
 
         if skip_provider_errors {
             crate::task::workspace::WorkspaceProjectGraph::discover_all_with_overrides_lenient(
-                &[&cargo, &node, &uv],
+                &[&cargo, &go, &node, &uv],
                 &monorepo_root,
                 &overrides,
             )
         } else {
             crate::task::workspace::WorkspaceProjectGraph::discover_all_with_overrides(
-                &[&cargo, &node, &uv],
+                &[&cargo, &go, &node, &uv],
                 &monorepo_root,
                 &overrides,
             )

src/task/workspace.rs

@@ -9,6 +9,7 @@ use serde::{Deserialize, Serialize};
 use super::{Task, TaskCacheConfig, task_sources::TaskOutputs};
 
 pub mod cargo;
+pub mod go;
 pub mod node;
 pub mod uv;