qemu-build

name	qemu-build
description	Use for configuring, reusing, building, or diagnosing QEMU build directories. Defaults to build and keeps agent-created logs and reports under a .oh-my-qemu task workspace.

QEMU Build

Use this operational skill when the task asks to inspect, configure, build, reconfigure, or diagnose a QEMU build.

Primitive Boundary

This primitive owns only build-directory inspection, configure/build commands, build logs, and build-failure diagnosis. It consumes an artifact root supplied by the caller and does not choose planning, verification, debug, or review workflow steps.

Hard policy boundary

Do not produce source code intended for QEMU upstream submission. Do not add DCO or review trailers.

Build directory rule

Default to build/ in the QEMU source tree. Reuse it when suitable.

Before creating or reconfiguring anything, inspect:

• build/config.log for the configure command;
• build/build.ninja for configured state;
• build/pyvenv/bin/meson for Meson commands;
• build/meson-logs/meson-log.txt for configure failures;
• build/meson-info/intro-buildoptions.json for options.

Create another directory only when needed to preserve a different configuration, such as sanitizer vs non-sanitizer.

Configure

From the QEMU source root:

mkdir -p build
cd build
../configure --target-list=<targets>

Common targets:

• x86_64-softmmu
• aarch64-softmmu
• riscv64-softmmu
• loongarch64-softmmu
• x86_64-linux-user
• aarch64-linux-user

Useful options:

• --enable-debug
• --enable-debug-info
• --enable-trace-backends=log
• --enable-asan
• --enable-tsan
• --enable-ubsan

Use ../configure --help for the checked-out QEMU version.

Reconfigure safely

Reconstruct the old command from build/config.log, then change only the needed option.

Preserve:

• target list unless the task changes it;
• debug/sanitizer/trace options;
• dependency/accelerator options;
• build directory evidence until diagnosis is complete.

Do not delete build/ to make an error disappear.

Build

From the source root:

ninja -C build

Prefer narrow targets when possible:

ninja -C build qemu-system-riscv64
ninja -C build tests/qtest/<test-name>

Use verbose mode only for diagnosis:

ninja -C build -v <target>

Failure classification

• Configure: missing dependency, unsupported option, Python/Meson issue, compiler mismatch.
• Compile: API/type/include/feature guard mismatch.
• Link: missing object in Meson, missing dependency, target-specific source not linked.
• Generated source: QAPI, trace-events, decodetree, or Meson generator input.
• Toolchain/host: sanitizer or compiler incompatibility.

For generated-source failures, fix the generator input, not generated files in build/.

Report

Write/report:

• PASS/FAIL/INCONCLUSIVE;
• source root and build dir;
• exact command;
• target list and key options;
• decisive failure excerpt;
• full log paths under .oh-my-qemu/<task-slug>/;
• what the build proves.

Upstream references

• QEMU code provenance and AI policy: docs/devel/code-provenance.rst.
• QEMU RFC qemu-build skill.
• Testing overview: docs/devel/testing/main.rst.