DLPX-93264 24.04 LTS upgrade: kernel builds fail due to rustc conflict

[palash-gandhi]

Problem:

Kernel builds using a 24.04 DE-based buildserver fail with:

23:15:00  Correcting dependencies...Starting pkgProblemResolver with broken count: 1
23:15:00  Starting 2 pkgProblemResolver with broken count: 1
23:15:00  Investigating (0) delphix-rust:amd64 < 1.0.0-1delphix.2025.01.23.02.41 @ii K Ib >
23:15:00  Broken delphix-rust:amd64 Conflicts on rustc:amd64 < none -> 1.75.0+dfsg0ubuntu1-0ubuntu7.1 @un uN >
23:15:00    Considering rustc:amd64 -1 as a solution to delphix-rust:amd64 1
23:15:00    Added rustc:amd64 to the remove list
23:15:00    Conflicts//Breaks against version 1.75.0+dfsg0ubuntu1-0ubuntu7 for rustc but that is not InstVer, ignoring
23:15:00    Conflicts//Breaks against version 1.74.1+dfsg0ubuntu1-0ubuntu13 for rustc-1.74 but that is not InstVer, ignoring
23:15:00    Fixing delphix-rust:amd64 via keep of rustc:amd64
23:15:00  Investigating (0) bindgen-0.65:amd64 < none -> 0.65.1+dfsg0-0ubuntu1 @un uN Ib >
23:15:00  Broken bindgen-0.65:amd64 Depends on rustc:amd64 < none | 1.75.0+dfsg0ubuntu1-0ubuntu7.1 @un uH > (>= 1.72.0+dfsg)
23:15:00    Considering rustc:amd64 -1 as a solution to bindgen-0.65:amd64 0
23:15:00    Holding Back bindgen-0.65:amd64 rather than change rustc:amd64
23:15:00  Investigating (0) linux-build-deps:amd64 < 6.8.0-47.47 @iU K Nb Ib >
23:15:00  Broken linux-build-deps:amd64 Depends on bindgen-0.65:amd64 < none | 0.65.1+dfsg0-0ubuntu1 @un uH >
23:15:00    Considering bindgen-0.65:amd64 0 as a solution to linux-build-deps:amd64 -2
23:15:00    Removing linux-build-deps:amd64 rather than change bindgen-0.65:amd64
23:15:00  Done
23:15:00   Done
...
...
23:15:08  mk-build-deps: Unable to install linux-build-deps at /usr/bin/mk-build-deps line 460.
23:15:08  mk-build-deps: Unable to install all build-dep packages
23:15:08  Error: failed command 'sudo mk-build-deps --install debian/control --tool apt-get -o Debug::pkgProblemResolver=yes --no-install-recommends --yes'

Example: https://ops-jenkins.eng-tools-prd.aws.delphixcloud.com/job/linux-pkg/job/os-upgrade/job/build-package/job/linux-kernel-generic/job/pre-push/48/consoleFull

On a DE-based buildserver delphix-rust's version is 1.0.0:

$ apt show delphix-rust
$ apt show delphix-rust
Package: delphix-rust
Version: 1.0.0-1delphix.2025.01.23.02.41
...
Provides: cargo, rust-gdb, rustc
Conflicts: cargo, rust-gdb, rustc

As I understand it, the problem is:

• delphix-rust:amd64: Conflicts with rustc:amd64.
• bindgen-0.65:amd64: Depends on rustc:amd64.
• linux-build-deps:amd64: Depends on bindgen-0.65:amd64.

Prakash helped shed some light and the issue turned out to be that bindgen-0.65 required rustc >1.72 but since delphix-rust's version 1.0.0 was not going to satisfy the dependency. As such, apt tried to install rustc 1.75 which conflicted with delphix-rust.

Solution:

Change the version of delphix-rust to be the actual version of rustc supplied by the virtual package.

Testing

build-package: https://ops-jenkins.eng-tools-prd.aws.delphixcloud.com/job/linux-pkg/job/os-upgrade/job/build-package/job/delphix-rust/job/pre-push/63/console
This change can only be fully tested after merging this change, building a buildserver and finally building the kernel. There is currently no easy way to test this process pre-push for os-upgrade.