Packaging Rust for Debian - part II
Let’s do another dive into packaging Rust for Debian with a slightly more complicated example.
One great tool in the packager’s toolbox is cargo-debstatus. By running it in the root of your crate you will get a list of your dependencies, together with information regarding its packaging status in Debian.
ripasso a part of the tree looks like below at the time of writing.
ripasso depends on
which depends on a number of other Rust libraries (and a number of native ones which aren’t shown here).
├── gpgme v0.9.2 │ ├── bitflags v1.2.1 (in debian) │ ├── conv v0.3.3 │ │ └── custom_derive v0.1.7 │ ├── cstr-argument v0.1.1 (in debian) │ ├── gpg-error v0.5.1 (in debian) │ ├── gpgme-sys v0.9.1 │ │ ├── libc v0.2.66 (in debian) │ │ └── libgpg-error-sys v0.5.1 (in debian) │ ├── libc v0.2.66 (in debian) │ ├── once_cell v1.3.1 (in debian) │ ├── smallvec v1.1.0 (in debian) │ └── static_assertions v1.1.0
One of the dependencies is static_assertions which is actually already packaged in Debian, but version 0.3.3 and we need 1.1.0. Let’s investigate how to fix this one.
In order to verify that we won’t break any other package by upgrading the existing Debian package to 1.1.0 we run list-rdeps.sh.
$ ./dev/list-rdeps.sh static-assertions APT cache is a bit old, update? [Y/n] n Versions of rust-static-assertions in unstable: librust-static-assertions-dev 0.3.3-2 Versions of rdeps of rust-static-assertions in unstable, that also exist in testing: librust-lexical-core-dev 0.4.3-1+b1 depends on librust-static-assertions-0.3+default-dev (>= 0.3.3-~~),
Here we see that the lexical-core package depends on static-assertions
and a quick
git clone and compilation confirms that it doesn’t compile with version 1.1.0.
We can take this one step further
$ ./dev/list-rdeps.sh lexical-core APT cache is a bit old, update? [Y/n] n Versions of rust-lexical-core in unstable: librust-lexical-core+correct-dev 0.4.3-1+b1 librust-lexical-core+default-dev 0.4.3-1+b1 librust-lexical-core-dev 0.4.3-1+b1 librust-lexical-core+dtoa-dev 0.4.3-1+b1 librust-lexical-core+grisu3-dev 0.4.3-1+b1 librust-lexical-core+ryu-dev 0.4.3-1+b1 librust-lexical-core+stackvector-dev 0.4.3-1+b1 Versions of rdeps of rust-lexical-core in unstable, that also exist in testing: librust-lexical-core+correct-dev 0.4.3-1+b1 depends on librust-lexical-core+table-dev (= 0.4.3-1+b1), librust-lexical-core+default-dev 0.4.3-1+b1 depends on librust-lexical-core+correct-dev (= 0.4.3-1+b1), librust-lexical-core+std-dev (= 0.4.3-1+b1), librust-nom+lexical-core-dev 5.0.1-4 depends on librust-lexical-core-0.4+default-dev, librust-nom+lexical-dev 5.0.1-4 depends on librust-lexical-core-0.4+default-dev,
And we see that nom depends on lexical-core.
$ ./dev/list-rdeps.sh nom APT cache is a bit old, update? [Y/n] n Versions of rust-nom in unstable: librust-nom+default-dev 5.0.1-4 librust-nom-dev 5.0.1-4 librust-nom+lazy-static-dev 5.0.1-4 librust-nom+lexical-core-dev 5.0.1-4 librust-nom+lexical-dev 5.0.1-4 librust-nom+regex-dev 5.0.1-4 librust-nom+regexp-dev 5.0.1-4 librust-nom+regexp-macros-dev 5.0.1-4 librust-nom+std-dev 5.0.1-4 Versions of rdeps of rust-nom in unstable, that also exist in testing: librust-cexpr-dev 0.3.3-1+b1 depends on librust-nom-4+default-dev, librust-nom-4+verbose-errors-dev, librust-dhcp4r-dev 0.2.0-1 depends on librust-nom-5+default-dev (>= 5.0.1-~~), librust-iso8601-dev 0.3.0-1 depends on librust-nom-4+default-dev, librust-nom-4+lazy-static-dev 4.2.3-3 depends on librust-nom-4-dev (= 4.2.3-3), librust-nom-4+regex-dev 4.2.3-3 depends on librust-nom-4-dev (= 4.2.3-3), librust-nom-4+regexp-macros-dev 4.2.3-3 depends on librust-nom-4-dev (= 4.2.3-3), librust-nom-4+regexp-dev (= 4.2.3-3), librust-nom-4+std-dev 4.2.3-3 depends on librust-nom-4-dev (= 4.2.3-3), librust-nom-4+alloc-dev (= 4.2.3-3), librust-nom+default-dev 5.0.1-4 depends on librust-nom+std-dev (= 5.0.1-4), librust-nom+lexical-dev (= 5.0.1-4), librust-nom+regexp-macros-dev 5.0.1-4 depends on librust-nom+regexp-dev (= 5.0.1-4), librust-nom+std-dev 5.0.1-4 depends on librust-nom+alloc-dev (= 5.0.1-4), librust-pktparse-dev 0.4.0-1 depends on librust-nom-4+default-dev (>= 4.2-~~), librust-rusticata-macros-dev 2.0.4-1 depends on librust-nom-5+default-dev, librust-tls-parser-dev 0.9.2-3 depends on librust-nom-5+default-dev, librust-weedle-dev 0.10.0-3 depends on librust-nom-4+default-dev,
And a lot of things depends on nom.
So in order to package
static_assertions so that we can package
gpgme we can choose one of three
- Package both versions of
nomdepends on to newer versions
- Patch version 0.4.3 of
lexical-coreto use a newer version of
Packaging both versions of
This is a working strategy, but packaging both means that we need to create a new package for
version 0.3 of
static_assertions. New packages in Debian go through the new queue, where a member
of the ftp masters team needs to manually verify so that it doesn’t contain any non-free software.
Therefore we will not choose this strategy.
nom and everything
nom depends on to newer versions
There exists a new version of
lexical-core that depend on
static_assertions 1, but the newer
nom is a beta version of
nom 6, and upgrading to that version would mean that we would
need to patch all the incompatibilities in the applications that use nom.
A lot of non-trivial work, specially as we in that case would like to upstream the patches so that the maintenance burden doesn’t grow too much.
Patching version 0.4.3 of
lexical-core to use a newer version of
It turns out that there is an upgrade commit
lexical-core that applies cleanly to version 0.4.3. This is what we will use.
So we take that commit as a patch and place it into the patches directory together with a series file that just lists what order to patches should be applied in.
That enables us to upgrade the
static_assertions package to version 1.1.0 without breaking
any other package.