Agent skill

Gdb

by mohitmishra786 in mohitmishra786/low-level-dev-skills

GDB debugger skill for C/C++ programs. An agent skill from mohitmishra786/low-level-dev-skills.

MITAuto-check passedDevelopment

Install Gdb

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gdb --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/debuggers/gdb .claude/skills/gdb && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "gdb" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb into .claude/skills/gdb/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gdb", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gdb --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/debuggers/gdb .agents/skills/gdb && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "gdb" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb into .agents/skills/gdb/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gdb", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gdb --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/debuggers/gdb .cursor/skills/gdb && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "gdb" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb into .cursor/skills/gdb/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gdb", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/mohitmishra786/low-level-dev-skills.git --path skills/debuggers/gdb

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gdb --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/debuggers/gdb .gemini/skills/gdb && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "gdb" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb into .gemini/skills/gdb/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gdb", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gdb

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/debuggers/gdb .github/skills/gdb && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "gdb" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb into .github/skills/gdb/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gdb", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gdb --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/debuggers/gdb .opencode/skills/gdb && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "gdb" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/debuggers/gdb into .opencode/skills/gdb/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gdb", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: gdb
GitHub stars: 253
Token cost: ~1.6k tokens
SKILL.md length: 341 words
Files: 3 (incl. references)
Skills in repo: 138
Repo updated: Jun 27, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

GDB debugger skill for C/C++ programs. An agent skill from mohitmishra786/low-level-dev-skills.

Works in 10 steps: Prerequisite: compile with debug info → Start GDB → Essential commands → …
Starting a GDB session
SKILL.md covers Purpose, Triggers, Workflow and Related skills
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Gdb is an agent skill from mohitmishra786/low-level-dev-skills. GDB debugger skill for C/C++ programs. Use when starting a GDB session, setting breakpoints, stepping through code, inspecting variables, debugging crashes, using reverse debugging (record/replay), remote debugging with gdbserver, or loading core dumps. Activates on queries about GDB commands, segfaults, hangs, watchpoints, conditional breakpoints, pretty-printers, Python GDB scripting, or multi-threaded debugging.

Its SKILL.md is about 1.6k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including reference files (for example `references/cheatsheet.md` and `references/scripting.md`).

It sits in Development, covering Responsive design and Debugging. It works with C++ and Python. The repository describes itself as: A curated suite of AI agent skills for systems and low-level programming with C/C++, Rust, and Zig toolchains, covering compilers, debuggers, profilers, build systems…. The licence is MIT.

When your agent uses it

Starting a GDB session
Setting breakpoints
Stepping through code
Inspecting variables

Example prompts

“/gdb”

Requirements

Python 3

Workflow steps

10 steps, taken from the step headings in SKILL.md.

Prerequisite: compile with debug info
Start GDB
Essential commands
Breakpoints and watchpoints
Inspect state
Multi-thread debugging
Reverse debugging (record/replay)
Remote debugging with gdbserver
Common problems
GDB init file (~/.gdbinit)

What it can do on your machine

Read from SKILL.md and the folder at commit bdc5847. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are gdb and bash).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Gdb loads about 1.6k tokens when it runs, and up to ~3.5k if it reads all its reference files. Until then it costs about 106 tokens; SKILL.md has 341 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~106
When it runs · the whole SKILL.md, loaded when a task matches: ~1.6k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~3.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from mohitmishra786/low-level-dev-skills at commit bdc5847, republished under its MIT licence (© mohitmishra786). 341 words, ~1,583 tokens.

Download SKILL.mdSave it as .claude/skills/gdb/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.

name: gdb
description: GDB debugger skill for C/C++ programs. Use when starting a GDB session, setting breakpoints, stepping through code, inspecting variables, debugging crashes, using reverse debugging (record/replay), remote debugging with gdbserver, or loading core dumps. Activates on queries about GDB commands, segfaults, hangs, watchpoints, conditional breakpoints, pretty-printers, Python GDB scripting, or multi-threaded debugging.

GDB

Purpose

Walk agents through GDB sessions from first launch to advanced workflows: crash diagnosis, reverse debugging, remote debugging, and multi-thread inspection.

Triggers

"My program segfaults / crashes — how do I debug it?"
"How do I set a breakpoint on condition X?"
"How do I inspect memory / variables in GDB?"
"How do I debug a remote embedded target?"
"GDB shows ?? frames / no source"
"How do I replay a bug deterministically?" (record/replay)

Workflow

1. Prerequisite: compile with debug info

Always compile with -g (GCC/Clang). Use -Og or -O0 for most debuggable code.

bash

gcc -g -Og -o prog main.c

For release builds: use -g -O2 and keep the binary with symbols (strip separately with objcopy).

2. Start GDB

bash

gdb ./prog                          # load binary
gdb ./prog core                     # load with core dump
gdb -p 12345                        # attach to running process
gdb --args ./prog arg1 arg2         # pass arguments
gdb -batch -ex 'run' -ex 'bt' ./prog  # non-interactive (CI)

3. Essential commands

Command	Shortcut	Effect
`run [args]`	`r`	Start the program
`continue`	`c`	Resume after break
`next`	`n`	Step over (source line)
`step`	`s`	Step into
`nexti`	`ni`	Step over (instruction)
`stepi`	`si`	Step into (instruction)
`finish`		Run to end of current function
`until N`		Run to line N
`return [val]`		Force return from function
`quit`	`q`	Exit GDB

4. Breakpoints and watchpoints

gdb

break main                          # break at function
break file.c:42                     # break at line
break *0x400abc                     # break at address
break foo if x > 10                 # conditional break
tbreak foo                          # temporary breakpoint (fires once)
rbreak ^mylib_.*                    # regex breakpoint on all matching functions

watch x                             # watchpoint: break when x changes
watch *(int*)0x601060               # watch memory address
rwatch x                            # break when x is read
awatch x                            # break on read or write

info breakpoints                    # list all breakpoints
delete 3                            # delete breakpoint 3
disable 3                           # disable without deleting
enable 3

5. Inspect state

gdb

print x                             # print variable
print/x x                           # print in hex
print *ptr                          # dereference pointer
print arr[0]@10                     # print 10 elements of array
display x                           # auto-print x on every stop
undisplay 1

info locals                         # all local variables
info args                           # function arguments
info registers                      # all CPU registers
info registers rip rsp rbp          # specific registers
x/10wx 0x7fff0000                   # examine 10 words at address
x/s 0x400abc                        # examine as string
x/i $rip                            # examine current instruction

backtrace                           # call stack (bt)
bt full                             # bt + local vars
frame 2                             # switch to frame 2
up / down                           # move up/down the stack

6. Multi-thread debugging

gdb

info threads                        # list threads
thread 3                            # switch to thread 3
thread apply all bt                 # backtrace all threads
thread apply all bt full            # full bt all threads
set scheduler-locking on            # pause other threads while stepping

7. Reverse debugging (record/replay)

Record requires target record-full or target record-btrace (Intel PT):

gdb

# Software record (slow but universal)
record                              # start recording
run
# ... trigger the bug ...
reverse-continue                    # go back to last break
reverse-next                        # step backwards
reverse-step
reverse-finish

# Intel Processor Trace (fast, hardware)
target record-btrace pt
run
# view instruction history
record instruction-history

8. Remote debugging with gdbserver

On target:

bash

gdbserver :1234 ./prog
# Or attach:
gdbserver :1234 --attach 5678

On host:

bash

gdb ./prog
(gdb) target remote 192.168.1.10:1234
(gdb) break main
(gdb) continue

For cross-compilation: use aarch64-linux-gnu-gdb on the host.

9. Common problems

Symptom	Cause	Fix
`No symbol table`	Binary not compiled with `-g`	Recompile with `-g`
`??` frames in backtrace	Missing debug info or stack corruption	Install debuginfo package; check for stack smash
`Cannot access memory at address`	Null dereference / freed memory	Check pointer before deref; use ASan
`SIGABRT` in backtrace	`abort()` or assertion failure	Go up frames to find the assertion
GDB hangs on `run`	Binary waiting for input	Redirect stdin: `run < /dev/null`
Breakpoint in wrong place	Optimiser moved code	Compile with `-Og`; or use `nexti`

10. GDB init file (~/.gdbinit)

gdb

set history save on
set history size 1000
set print pretty on
set print array on
set print array-indexes on
set pagination off
set confirm off

For a command cheatsheet, see references/cheatsheet.md. For pretty-printers and Python scripting, see references/scripting.md.

Use skills/debuggers/core-dumps for loading core files
Use skills/debuggers/lldb for LLDB-based workflows
Use skills/runtimes/sanitizers to catch bugs before needing the debugger
Use skills/compilers/gcc for -g flag details

Files

SKILL.md and 2 other files (references) in skills/debuggers/gdb of mohitmishra786/low-level-dev-skills.

SKILL.md
references/cheatsheet.md
references/scripting.md

Open the folder on GitHubat commit bdc5847

Compare with similar skills

Gdb next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Gdb compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Gdb this skillmohitmishra786/low-level-dev-skills	253	—	~1.6k	Automated safety check: Pass	MIT	3 mo ago
Dbgtheodo-group/debug-that	158	—	~2.5k	Automated safety check: Pass	MIT	yesterday
Ue Live DebuggingJasonMa0012/MooaToon	750	—	~2.9k	Automated safety check: Notes	Custom licence	21 days ago
MCP Debuggerdebugmcp/mcp-debugger	172	—	~3.8k	Automated safety check: Pass	MIT	2 days ago
Tilelang Debug Helpertile-ai/tilelang-ascend	402	—	~1.7k	Automated safety check: Notes	MIT	yesterday
SlintMoosync/Moosync	259	—	~2.4k	Automated safety check: Pass	GPL-3.0	8 days ago

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Questions about Gdb

What does Gdb do?

GDB debugger skill for C/C++ programs. An agent skill from mohitmishra786/low-level-dev-skills. Gdb is an agent skill from mohitmishra786/low-level-dev-skills. GDB debugger skill for C/C++ programs.

When should I use Gdb?

Gdb fits situations like: starting a GDB session; setting breakpoints; stepping through code; inspecting variables.

How do I install Gdb in Claude Code?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a claude-code`. Or copy the skill folder (skills/debuggers/gdb in mohitmishra786/low-level-dev-skills) into .claude/skills/gdb in your project. Claude Code loads it when a task matches its description.

How do I install Gdb in Codex?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a codex`. Or copy the skill folder (skills/debuggers/gdb in mohitmishra786/low-level-dev-skills) into .agents/skills/gdb in your project. Codex loads it when a task matches its description.

Can I use Gdb in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mohitmishra786/low-level-dev-skills --skill gdb -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/gdb, .gemini/skills/gdb, .github/skills/gdb and .opencode/skills/gdb in your project.

What does Gdb need to run?

SKILL.md names no scripts, command-line tools or credentials: Gdb is instructions for the agent only. Our summary lists: Python 3.

Does Gdb access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Gdb safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Gdb use?

Gdb is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Gdb use?

About 1.6k tokens (SKILL.md is roughly 6.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.9k tokens, read only when the agent opens those files.

What are the alternatives to Gdb?

Skills that share tags, products or a category with Gdb: Dbg (theodo-group/debug-that, 158 stars), Ue Live Debugging (JasonMa0012/MooaToon, 750 stars), MCP Debugger (debugmcp/mcp-debugger, 172 stars) and Tilelang Debug Helper (tile-ai/tilelang-ascend, 402 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Gdb?

mohitmishra786 (a GitHub user) maintains it in mohitmishra786/low-level-dev-skills, which has 253 GitHub stars. The repository holds 138 skills in this directory. The repository was last updated on June 27, 2026.

Source: mohitmishra786/low-level-dev-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Gdb

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

GDB

Purpose

Triggers

Workflow

1. Prerequisite: compile with debug info

2. Start GDB

3. Essential commands

4. Breakpoints and watchpoints

5. Inspect state

6. Multi-thread debugging

7. Reverse debugging (record/replay)

8. Remote debugging with gdbserver

9. Common problems

10. GDB init file (~/.gdbinit)

Related skills

Files

Compare with similar skills

Similar skills

More from mohitmishra786/low-level-dev-skills

Related

Questions about Gdb