bazel

Name: bazel
Author: mohitmishra786

219installs19forks

How to install bazel?

mohitmishra786/low-level-dev-skills/bazel

$npx -y skills add mohitmishra786/low-level-dev-skills --skill bazel

Installs into the current project.

Summary

Bazel build system skill for C/C++ projects. Use when writing BUILD files with cc_library and cc_binary rules, registering toolchains, configuring remote execution, debugging sandbox issues, using query and cquery for dependency graphs, or migrating from CMake to Bazel. Activates

Files · 1

View on GitHub

SKILL.md

1	# Bazel
2
3	## Purpose
4
5	Guide agents through Bazel for C/C++ projects: writing BUILD files, cc_library/cc_binary rules, toolchain registration, remote execution, dependency graph queries, Bzlmod dependency management, and sandbox debugging.
6
7	## Triggers
8
9	- "How do I write a Bazel BUILD file for a C++ library?"
10	- "How do I add external dependencies with Bzlmod?"
11	- "How do I debug Bazel sandbox errors?"
12	- "How do I query the Bazel dependency graph?"
13	- "How do I set up remote execution with Bazel?"
14	- "How do I register a custom C++ toolchain?"
15
16	## Workflow
17
18	### 1. Workspace structure
19
20	```
21	my-project/
22	├── MODULE.bazel # Bzlmod dependency file (Bazel ≥6)
23	├── WORKSPACE # legacy (still needed for some features)
24	├── BUILD # root build file
25	├── src/
26	│ ├── BUILD
27	│ └── main.cc
28	└── lib/
29	├── BUILD
30	├── mylib.cc
31	└── mylib.h
32	```
33
34	### 2. Basic BUILD file — cc_library / cc_binary
35
36	```python
37	# lib/BUILD
38	cc_library(
39	name = "mylib",
40	srcs = ["mylib.cc"],
41	hdrs = ["mylib.h"],
42	copts = ["-Wall", "-Wextra", "-std=c++17"],
43	visibility = ["//visibility:public"],
44	deps = [
45	"@com_google_absl//absl/strings", # external dep
46	"//util:helpers", # internal dep
47	],
48	)
49
50	cc_test(
51	name = "mylib_test",
52	srcs = ["mylib_test.cc"],
53	deps = [
54	":mylib",
55	"@com_google_googletest//:gtest_main",
56	],
57	)
58	```
59
60	```python
61	# src/BUILD
62	cc_binary(
63	name = "main",
64	srcs = ["main.cc"],
65	deps = ["//lib:mylib"],
66	linkopts = ["-lpthread"],
67	)
68	```
69
70	```bash
71	# Build
72	bazel build //src:main
73	bazel build //... # build everything
74
75	# Test
76	bazel test //lib:mylib_test
77	bazel test //... # run all tests
78
79	# Run
80	bazel run //src:main -- arg1 arg2
81
82	# Output path
83	bazel-bin/src/main
84	```
85
86	### 3. Bzlmod — modern dependency management
87
88	```python
89	# MODULE.bazel
90	module(
91	name = "my_project",
92	version = "1.0",
93	)
94
95	bazel_dep(name = "abseil-cpp", version = "20240116.2")
96	bazel_dep(name = "googletest", version = "1.14.0")
97	bazel_dep(name = "rules_cc", version = "0.0.9")
98	bazel_dep(name = "platforms", version = "0.0.8")
99
100	# For http_archive deps not yet in BCR (Bazel Central Registry)
101	# Use module extensions
102	```
103
104	```bash
105	# Check available versions
106	bazel mod graph \| head -30
107
108	# Show dependency tree
109	bazel mod deps --depth=2
110	```
111
112	### 4. Dependency graph queries
113
114	```bash
115	# Show all dependencies of a target
116	bazel query "deps(//src:main)"
117
118	# Find reverse dependencies (who depends on this?)
119	bazel query "rdeps(//..., //lib:mylib)"
120
121	# Find what changed between builds
122	bazel query "filter('//lib', deps(//src:main))"
123
124	# cquery — configuration-aware query
125	bazel cquery "deps(//src:main)" --output=files
126
127	# Show include paths for a target
128	bazel cquery "//lib:mylib" --output=build
129
130	# Find cycles in the build graph
131	bazel query --nohost_deps --noimplicit_deps \
132	"somepath(//src:main, //lib:mylib)"
133
134	# aquery — action graph (shows compiler flags, inputs, outputs)
135	bazel aquery "//src:main"
136	bazel aquery "//src:main" --output=jsonproto \| jq '.actions[0].arguments'
137	```
138
139	### 5. Toolchain registration
140
141	```python
142	# platforms/BUILD
143	platform(
144	name = "linux_x86_64",
145	constraint_values = [
146	"@platforms//os:linux",
147	"@platforms//cpu:x86_64",
148	],
149	)
150
151	# toolchains/BUILD
152	cc_toolchain_suite(
153	name = "my_toolchain",
154	toolchains = {
155	"k8": ":my_k8_toolchain",
156	},
157	)
158
159	cc_toolchain(
160	name = "my_k8_toolchain",
161	all_files = ":empty",
162	compiler_files = ":compiler_wrapper",
163	# ... other file groups
164	)
165
166	toolchain(
167	name = "my_cc_toolchain",
168	toolchain = ":my_k8_toolchain",
169	toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
170	target_compatible_with = ["@platforms//os:linux"],
171	)
172	```
173
174	```python
175	# MODULE.bazel — register toolchain
176	register_toolchains("//toolchains:my_cc_toolchain")
177	```
178
179	### 6. Remote execution
180
181	```bash
182	# Use --remote_executor flag
183	bazel build //... \
184	--remote_executor=grpc://buildgrid.example.com:50051 \
185	--remote_instance_name=main
186
187	# Google Cloud Build Remote Execution
188	bazel build //... \
189	--remote_executor=remotebuildexecution.googleapis.com \
190	--remote_instance_name=projects/my-project/instances/default \
191	--google_default_credentials
192
193	# Caching (without remote execution)
194	bazel build //... \
195	--remote_cache=grpc://cache.example.com:9092
196
197	# Show what's cached
198	bazel build //... --remote_upload_local_results=true
199	```
200
201	### 7. Sandbox debugging
202
203	```bash
204	# Show sandbox inputs and outputs
205	bazel build //src:main --sandbox_debug
206
207	# Run build with verbos

People who liked this also viewed

6 picks

Type

bazel

219installs19forks

View on GitHub

How to install bazel?

mohitmishra786/low-level-dev-skills/bazel

$npx -y skills add mohitmishra786/low-level-dev-skills --skill bazel

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Bazel
2
3	## Purpose
4
5	Guide agents through Bazel for C/C++ projects: writing BUILD files, cc_library/cc_binary rules, toolchain registration, remote execution, dependency graph queries, Bzlmod dependency management, and sandbox debugging.
6
7	## Triggers
8
9	- "How do I write a Bazel BUILD file for a C++ library?"
10	- "How do I add external dependencies with Bzlmod?"
11	- "How do I debug Bazel sandbox errors?"
12	- "How do I query the Bazel dependency graph?"
13	- "How do I set up remote execution with Bazel?"
14	- "How do I register a custom C++ toolchain?"
15
16	## Workflow
17
18	### 1. Workspace structure
19
20	```
21	my-project/
22	├── MODULE.bazel # Bzlmod dependency file (Bazel ≥6)
23	├── WORKSPACE # legacy (still needed for some features)
24	├── BUILD # root build file
25	├── src/
26	│ ├── BUILD
27	│ └── main.cc
28	└── lib/
29	├── BUILD
30	├── mylib.cc
31	└── mylib.h
32	```
33
34	### 2. Basic BUILD file — cc_library / cc_binary
35
36	```python
37	# lib/BUILD
38	cc_library(
39	name = "mylib",
40	srcs = ["mylib.cc"],
41	hdrs = ["mylib.h"],
42	copts = ["-Wall", "-Wextra", "-std=c++17"],
43	visibility = ["//visibility:public"],
44	deps = [
45	"@com_google_absl//absl/strings", # external dep
46	"//util:helpers", # internal dep
47	],
48	)
49
50	cc_test(
51	name = "mylib_test",
52	srcs = ["mylib_test.cc"],
53	deps = [
54	":mylib",
55	"@com_google_googletest//:gtest_main",
56	],
57	)
58	```
59
60	```python
61	# src/BUILD
62	cc_binary(
63	name = "main",
64	srcs = ["main.cc"],
65	deps = ["//lib:mylib"],
66	linkopts = ["-lpthread"],
67	)
68	```
69
70	```bash
71	# Build
72	bazel build //src:main
73	bazel build //... # build everything
74
75	# Test
76	bazel test //lib:mylib_test
77	bazel test //... # run all tests
78
79	# Run
80	bazel run //src:main -- arg1 arg2
81
82	# Output path
83	bazel-bin/src/main
84	```
85
86	### 3. Bzlmod — modern dependency management
87
88	```python
89	# MODULE.bazel
90	module(
91	name = "my_project",
92	version = "1.0",
93	)
94
95	bazel_dep(name = "abseil-cpp", version = "20240116.2")
96	bazel_dep(name = "googletest", version = "1.14.0")
97	bazel_dep(name = "rules_cc", version = "0.0.9")
98	bazel_dep(name = "platforms", version = "0.0.8")
99
100	# For http_archive deps not yet in BCR (Bazel Central Registry)
101	# Use module extensions
102	```
103
104	```bash
105	# Check available versions
106	bazel mod graph \| head -30
107
108	# Show dependency tree
109	bazel mod deps --depth=2
110	```
111
112	### 4. Dependency graph queries
113
114	```bash
115	# Show all dependencies of a target
116	bazel query "deps(//src:main)"
117
118	# Find reverse dependencies (who depends on this?)
119	bazel query "rdeps(//..., //lib:mylib)"
120
121	# Find what changed between builds
122	bazel query "filter('//lib', deps(//src:main))"
123
124	# cquery — configuration-aware query
125	bazel cquery "deps(//src:main)" --output=files
126
127	# Show include paths for a target
128	bazel cquery "//lib:mylib" --output=build
129
130	# Find cycles in the build graph
131	bazel query --nohost_deps --noimplicit_deps \
132	"somepath(//src:main, //lib:mylib)"
133
134	# aquery — action graph (shows compiler flags, inputs, outputs)
135	bazel aquery "//src:main"
136	bazel aquery "//src:main" --output=jsonproto \| jq '.actions[0].arguments'
137	```
138
139	### 5. Toolchain registration
140
141	```python
142	# platforms/BUILD
143	platform(
144	name = "linux_x86_64",
145	constraint_values = [
146	"@platforms//os:linux",
147	"@platforms//cpu:x86_64",
148	],
149	)
150
151	# toolchains/BUILD
152	cc_toolchain_suite(
153	name = "my_toolchain",
154	toolchains = {
155	"k8": ":my_k8_toolchain",
156	},
157	)
158
159	cc_toolchain(
160	name = "my_k8_toolchain",
161	all_files = ":empty",
162	compiler_files = ":compiler_wrapper",
163	# ... other file groups
164	)
165
166	toolchain(
167	name = "my_cc_toolchain",
168	toolchain = ":my_k8_toolchain",
169	toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
170	target_compatible_with = ["@platforms//os:linux"],
171	)
172	```
173
174	```python
175	# MODULE.bazel — register toolchain
176	register_toolchains("//toolchains:my_cc_toolchain")
177	```
178
179	### 6. Remote execution
180
181	```bash
182	# Use --remote_executor flag
183	bazel build //... \
184	--remote_executor=grpc://buildgrid.example.com:50051 \
185	--remote_instance_name=main
186
187	# Google Cloud Build Remote Execution
188	bazel build //... \
189	--remote_executor=remotebuildexecution.googleapis.com \
190	--remote_instance_name=projects/my-project/instances/default \
191	--google_default_credentials
192
193	# Caching (without remote execution)
194	bazel build //... \
195	--remote_cache=grpc://cache.example.com:9092
196
197	# Show what's cached
198	bazel build //... --remote_upload_local_results=true
199	```
200
201	### 7. Sandbox debugging
202
203	```bash
204	# Show sandbox inputs and outputs
205	bazel build //src:main --sandbox_debug
206
207	# Run build with verbos

People who liked this also viewed

6 picks

Type