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.
For ripasso
a part of the tree looks like below at the time of writing. ripasso
depends on gpgme
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
different strategies:
- Package both versions of
static_assertions
- Upgrade
lexical-core
,nom
and everythingnom
depends on to newer versions - Patch version 0.4.3 of
lexical-core
to use a newer version ofstatic_assertions
Packaging both versions of static_assertions
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.
Upgrading lexical-core
, 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
version of 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 static_assertions
It turns out that there is an upgrade commit
in 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.