pkh/README.md

# pkh

`pkh` is a packaging helper for Debian/Ubuntu packages.

![](.github/pkh.gif)

## Installation

From crates.io:

```
cargo install pkh
```

Or build from source (the same system packages are needed either way):

```
sudo apt install pkg-config libssl-dev libgpg-error-dev libgpgme-dev
git clone https://git.vhaudiquet.fr/vhaudiquet/pkh.git
cd pkh
cargo install --path .
```

At runtime pkh shells out to the Debian packaging toolchain (git,
dpkg-dev, quilt, mmdebstrap, lintian, pristine-tar, autopkgtest, ...):
install the ones your workflows use, or build the classic snap from
`snap/snapcraft.yaml` (`snapcraft pack`), which carries them.

## Usage and features

### Basic concepts

`pkh` aims at wrapping the different debian tools and workflows 
(`git`, `git-ubuntu`, `pull-debian-sources`, `pull-lp-sources`, `pull-ppa-sources`,
`dch`, `dpkg-buildpackage`, `sbuild`, `dpkg-source`, `quilt`, ...) into one tool, that
would have the same interface for everything, while being smarter at integrating all workflows.

Thus, `pkh` uses similar options for all subcommands (with very few command-specific options):
```
Options:
  -s, --series <series>    Target package distribution series
  -d, --dist <dist>        Target package distribution (debian, ubuntu)
  -v, --version <version>  Target package version
  -a, --arch <arch>        Target architecture (amd64, arm64, riscv64, ...)
  -p, --pocket <pocket>    Target distribution pocket (updates, security, proposed, ...)
      --ppa <ppa>          Do the action in/for a specific PPA
```

Commands and workflows include:
```
Commands:
  new    Scaffold a new Debian source package (buildable right away)
  pull   Pull a source package from the archive or git
  chlog  Auto-generate changelog entry, editing it, committing it afterwards
  build  Build the source package (into a .dsc)
  put    Upload the built source package to a PPA
  deb    Build the source package into binary package (.deb)
  test   Run the package's DEP-8 as-installed tests (autopkgtests)
  lint   Lint the package (lintian wrapper + pkh-native checks)
  prune  Prune residual pkh build artifacts and caches
  help   Print this message or the help of the given subcommand(s)

Options:
  -h, --help     Print help
  -V, --version  Print version
```

### Examples

A typical workflow to patch an Ubuntu package `hello` on the development release could be:
```
# Obtain the package source
git ubuntu clone hello
cd hello
# Apply the patch to the package
...
dpkg-source --commit
# Increment version number
dch
# Test that the patch builds
git ubuntu export-orig
dpkg-buildpackage -S -I -i -nc -d
sbuild --dist resolute --arch amd64 ../hello_xxx.dsc
# Upload the package to a ppa
dput ppa:user/hello_xxx ../hello_xxx_source.changes
# Commit the changes to git
git add debian/patches/xxx.patch
git commit -m "Applied patch xxx"
git add debian/changelog
git commit -m "changelog"
git checkout -b xxx
git push xxx user-fork
```

That is a lot of different tools and operations. With pkh, the same workflow:
```
# Obtain the package source (and orig tarball)
pkh pull hello # needs -d ubuntu if you are not running Ubuntu
# Apply the patch to the package
...
git add debian/patches/xxx.patch
git commit -m "Applied patch xxx"
pkh chlog
git add debian/changelog
git commit -m "d/changelog"
# Test that the package builds
pkh build
pkh deb
# Upload the package to a ppa
pkh put --ppa user/hello_xxx
# Push the commits to your fork
git push xxx user-fork
```

`pkh chlog` edits `debian/changelog` by default; point it at another file
with `--file <path>` (`-f`).

`pkh chlog` walks the commit history back to the previous changelog entry.
Without a version tag, that search is capped at the last 500 commits
(`--limit <n>`, `0` = unlimited): beyond the cap, the entry simply starts
at the oldest commit searched, which keeps the run fast on large histories.

### Incremental builds (build records)

Every `pkh deb` build records its metadata under
`/var/tmp/pkh/sessions/<target>/<id>/`: the manifest (identity, fork
lineage, outcome, the sha of the chroot tarball it used) and a full
`log/build.log` tee of the build output. The chroot itself is per-run
scratch — extracted fresh from the sha-verified mmdebstrap tarball cache
on every run and removed at the end, plain and `--incremental` alike —
so records stay small. What `--incremental` buys is the record's
**staged tree** (`tree-upper/`): the overlay upperdir where the build's
writes land, holding the compiled objects.

Fresh chroots do not mean fresh downloads: every chroot's
`/var/cache/apt/archives` is a bind mount over a shared apt download
cache at `/var/tmp/pkh/apt-cache/<series>-<arch>/`, which the installs
of one run fill and the next runs reuse (apt is configured to keep the
downloaded packages, and an `apt-get autoclean` at the end of each run
drops the debs the archive no longer serves). `pkh prune` removes the
caches untouched for a week.

Fresh chroots do not mean fresh compiles either: every run's chroot
gets a shared ccache (at `/var/tmp/pkh/ccache/<target>/`, mounted at
`/var/cache/pkh-ccache`) wired in through a compiler PATH shim —
`gcc`, `g++`, `cc` and `c++` resolve to ccache — with content-keyed
cache checks (`CCACHE_COMPILERCHECK=content`), so cache hits survive
the fresh toolchain of a new chroot. The cache is capped at 10G per
target (override with `PKH_CCACHE_MAXSIZE`); `pkh deb --no-ccache`
bypasses the shim and cache entirely, an escape hatch for rules that
mishandle compiler wrappers (kbuild-style flavour configs).

`--incremental` forks a previous record — a copy, the base is never
modified — so a failed run can never destroy the last-good state it was
built from. The staged tree is carried only when the base's recorded
tarball sha still matches the cache (the toolchain did not move) and the
changelog version is unchanged; otherwise the fork builds from a fresh
tree:

```
pkh deb                 # plain run: fresh chroot, fresh tree; the
                        # record keeps only metadata and the log
                        # (nothing is kept even on failure or
                        # interrupt)
pkh deb --incremental   # fork the newest successful record of the
                        # target (among the last five carrying a staged
                        # tree) and keep this run's staged tree, for
                        # the next fork to carry
pkh deb --incremental <id>
                        # fork that exact record (see `pkh deb list`);
                        # a failed record is fine if its staged tree is
pkh deb list            # the records of this tree: id, outcome,
                        # version, fork lineage, staged-tree state, age
pkh deb log [-f] [<id>] # print a record's build log; -f follows a
                        # live build
pkh deb --no-ccache     # build without the shared compile cache
```

Each target keeps at most five staged trees: when a sixth is retained,
the oldest degrades to a metadata-only record (manifest and log stay),
and `pkh prune` removes records untouched for a week. `pkh deb
--incremental` never forks a record built for a different
series/architecture.

Packages whose `debian/rules` keeps an input-untracked stamp cache (the
kernels' `debian/stamps`) declare it in the quirks data
(`resume_clear`): forked builds drop the cache so the wrapper steps —
including the kernel's flavour config export — re-run over the
incremental inner builds, and a config edit is never silently ignored.
A build killed hard (OOM) can leave its chroot behind; the next run of
that target sweeps it (unmounting and escalating through sudo when
needed), and `pkh prune` collects the rest.

On a pinned runner — a machine that must resolve every package from one
mirror, typically a caching proxy — `pkh deb --mirror <url>` builds the
chroot and resolves every package from that base URL: the mirror is
passed to mmdebstrap at bootstrap, so the chroot tarball's apt sources
carry it and every apt inside the build follows. The mirror must serve
every suite and architecture the build resolves (the security pocket
and, for `--cross` builds, the target architecture's archive included);
PPAs and other third-party sources are left alone. The tarball cache is
keyed per mirror, so pinned and unpinned builds keep separate tarballs
(and `--incremental` records never fork across a mirror change).

### Running the DEP-8 tests

`pkh test` runs the package's as-installed tests (`debian/tests/control`,
declared by `Testsuite: autopkgtest` in `debian/control`) through a
native runner on a pkh testbed, and reports one verdict per test:

```
pkh test                 # test this tree: builds it first if needed
pkh test --mode local    # on the current context, no isolation
pkh test --mode vm --image img.qcow2   # in a VM, via autopkgtest
pkh test --json --fail-on skip         # CI-shaped
pkh test --list-tests    # what does this package test?
```

By default the tests run in an ephemeral unshare chroot bootstrapped
from the same cached tarballs as `pkh deb`, against the binaries pkh deb
just built next to the tree (stale or missing output is rebuilt first;
`--no-build` refuses, `--debs` overrides). Pockets and PPAs resolve test
dependencies like in `pkh deb` (`-p`, `--ppa`), and `--test-name`,
`--skip-test`, `--shell-fail` and `--setup-commands` cover the day-to-day
debugging loop. Tests needing a real machine (`isolation-machine`,
`needs-reboot`) run only in `--mode vm`, which execs the installed
`autopkgtest` with its qemu runner.

Exit codes: 0 all tests passed (skips and flaky allowed), 1 at least one
test failed (or a `--fail-on` trigger), 2 runtime errors (no declared
tests, no usable testbed, ...).

## Future improvement ideas

- pull: try to fetch the correct git branch for series on Debian
- deb: asynchronous build, detachable and monitorable
- put: allow uploads to Debian or Ubuntu archives
- pull: cache Sources.gz files to improve speed
- pull: 'pkh pull' in a package tree should git pull and re-fetch orig tgz