ci: use absolute cache paths in Buildkite

Author: lox

.buildkite/cache-env.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+checkout_path="${BUILDKITE_BUILD_CHECKOUT_PATH:-$(pwd)}"
+cache_root="${checkout_path}/.buildkite/cache-volume"
+
+mkdir -p \
+  "${cache_root}/go/build" \
+  "${cache_root}/go/pkg/mod" \
+  "${cache_root}/golangci-lint"
+
+export GOCACHE="${cache_root}/go/build"
+export GOMODCACHE="${cache_root}/go/pkg/mod"
+export GOLANGCI_LINT_CACHE="${cache_root}/golangci-lint"

.buildkite/pipeline.release.yml

@@ -1,10 +1,6 @@
 agents:
   queue: hosted
 
-x-cache-env: &cache_env
-  GOCACHE: .buildkite/cache-volume/go/build
-  GOMODCACHE: .buildkite/cache-volume/go/pkg/mod
-
 x-mise-plugin: &mise_plugin
   buildkite-plugins/mise#v1.1.1: ~
 
@@ -22,9 +18,8 @@ steps:
       - POSTHOG_API_KEY
       - OAUTH_CLIENT_ID
     env:
-      <<: *cache_env
       GOOS: "{{matrix}}"
-    command: ".buildkite/release.sh release --clean --split"
+    command: '. .buildkite/cache-env.sh && .buildkite/release.sh release --clean --split'
     plugins:
       - *mise_plugin
 
@@ -44,7 +39,6 @@ steps:
     artifact_paths:
       - dist/**/*
     env:
-      <<: *cache_env
       AWS_REGION: us-east-1
     secrets:
       - POSTHOG_API_KEY
@@ -65,4 +59,4 @@ steps:
           download:
             - dist/**/*
       - *mise_plugin
-    command: ".buildkite/release.sh continue --merge"
+    command: '. .buildkite/cache-env.sh && .buildkite/release.sh continue --merge'

.buildkite/pipeline.yml

@@ -1,30 +1,22 @@
 agents:
   queue: hosted
 
-x-cache-env: &cache_env
-  GOCACHE: .buildkite/cache-volume/go/build
-  GOMODCACHE: .buildkite/cache-volume/go/pkg/mod
-  GOLANGCI_LINT_CACHE: .buildkite/cache-volume/golangci-lint
-
 x-mise-plugin: &mise_plugin
   buildkite-plugins/mise#v1.1.1: ~
 
 cache: ".buildkite/cache-volume"
 
 steps:
   - name: ":golangci-lint: lint"
-    command: golangci-lint run --verbose --timeout 3m
-    env:
-      <<: *cache_env
+    command: '. .buildkite/cache-env.sh && golangci-lint run --verbose --timeout 3m'
     plugins:
       - *mise_plugin
 
   - name: ":go: test"
     artifact_paths:
       - cover-tree.svg
-    env:
-      <<: *cache_env
     commands:
+      - . .buildkite/cache-env.sh
       - go test -coverprofile cover.out ./...
       - go run github.com/nikolaydubina/go-cover-treemap@v1.5.1 -coverprofile cover.out > cover-tree.svg
       - echo '<details><summary>Coverage tree map</summary><img src="artifact://cover-tree.svg" alt="Test coverage tree map" width="70%"></details>' | buildkite-agent annotate --style "info"
@@ -44,9 +36,8 @@ steps:
       - POSTHOG_API_KEY
       - OAUTH_CLIENT_ID
     env:
-      <<: *cache_env
       GOOS: "{{matrix}}"
-    command: ".buildkite/release.sh release --clean --snapshot --split"
+    command: '. .buildkite/cache-env.sh && .buildkite/release.sh release --clean --snapshot --split'
     plugins:
       - *mise_plugin