version: "1.0.0"

SPDX-FileCopyrightText: Copyright (c) 2026 Process Mission

SPDX-License-Identifier: MIT

name: qemu-build description: Use for configuring, reusing, building, or diagnosing named QEMU build directories under source-root builds/, including target-specific, debug, sanitizer, and trace configurations.

QEMU Build

Audit workflow

For non-trivial workspace writes, use a stable .oh-my-qemu/<task-slug>/ directory and create only needed entries:

.oh-my-qemu/<task-slug>/
├── audit.md      # Baseline, scope, decisions, evidence, verification, and gaps
├── commands.md   # Redacted commands, working directories, and results
├── logs/         # Decisive build, test, runtime, or diagnostic logs
├── scripts/      # Temporary scripts, probes, parsers, and harnesses
└── output/       # Generated deliverables, dependencies, and non-QEMU binaries

Before changing source or mutable artifacts, record the workspace root, revision, git status --short, pre-existing changes, goal, scope, and acceptance checks in audit.md. Log exact redacted commands and results in commands.md; record revisions, configurations, tool versions, and hashes when they affect reproducibility. Separate observations from inferences and edit source only when requested.

Keep QEMU builds under source-root builds/build-<target>/; put third-party dependencies and non-QEMU binaries in task output/. Before writing audit artifacts or configuring QEMU in a Git worktree, add .agents/, .oh-my-qemu/, and builds/ to the repository-local file from git rev-parse --git-path info/exclude; preserve existing entries and avoid duplicates. Never stage or commit those directories. At handoff, verify them absent from git status --short. Report the task directory and unresolved gaps.

QEMU upstream boundary

QEMU's official GitLab and mailing lists are upstream project channels. A patch becomes an upstream contribution when sent to the mailing-list recipients selected through MAINTAINERS; do not prepare or send agent-generated patches for that submission. Local branches, commits, patch files, pushes, and pull requests are not by themselves QEMU upstream contributions. Perform those Git actions only when requested and follow the workspace's Git policy.

Build directory rule

Use a descriptive directory under source-root builds/ for every QEMU configuration. Derive the name from the target and important variant, for example:

• builds/build-aarch64/;
• builds/build-riscv64-debug/;
• builds/build-x86_64-asan/.

Do not configure QEMU in build/, the source root, or the task output/ directory. Reuse a named build only when its recorded configuration matches the task.

Before creating or reconfiguring anything, inspect:

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

Create another named directory for a materially different target or configuration, such as sanitizer versus non-sanitizer.

Configure

From the QEMU source root:

mkdir -p builds/build-aarch64
cd builds/build-aarch64
../../configure --target-list=aarch64-softmmu

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

From that build directory, use ../../configure --help for the checked-out QEMU version.

Reconfigure safely

Reconstruct the old command from <build-dir>/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 a named build directory merely to make an error disappear. Keep its decisive logs until the failure is classified.

Build

From the source root:

ninja -C builds/build-aarch64

Prefer narrow targets when possible:

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

Use verbose mode only for diagnosis:

ninja -C builds/build-riscv64 -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 builds/build-<target>/.

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.
• Testing overview: docs/devel/testing/main.rst.