[Regression] Breaks relationship w/ flash-kernel uses wrong version

[dann frazier]

We provide a "Breaks" relationship with flash-kernel to make sure we have a new enough flash-kernel to support compressed images. In zesty, this support was added in 3.0~rc.4ubuntu64. In xenial, this was SRU'd into version 3.0~rc.4ubuntu62.2.

The previous edge kernel had a correct Breaks statement for xenial:

root@pearl:~# apt show linux-image-4.10.0-24-generic | grep Breaks

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Breaks: flash-kernel (<< 3.0~rc.4ubuntu62.2)

But the current upload is using the correct version for *zesty*:

root@pearl:~# apt show linux-image-4.10.0-25-generic | grep Breaks

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Breaks: flash-kernel (<< 3.0~rc.4ubuntu64)

[dann frazier (dannf)]

Note that the impact here is that apt will not want to install the metapackage until you remove flash-kernel. Though the user can workaround this by removing flash-kernel, apt doesn't give any hints about that until you dig deeper:

root@pearl:~# apt install linux-image-generic-hwe-16.04-edge
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 linux-image-generic-hwe-16.04-edge : Depends: linux-image-4.10.0-25-generic but it is not going to be installed
                                      Depends: linux-image-extra-4.10.0-25-generic but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

root@pearl:~# apt install linux-image-4.10.0-25-generic
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
  devio
Use 'apt autoremove' to remove it.
Suggested packages:
  fdutils linux-doc-4.10.0 | linux-source-4.10.0 linux-tools
  linux-headers-4.10.0-25-generic
Recommended packages:
  flash-kernel
The following packages will be REMOVED:
  flash-kernel
The following NEW packages will be installed:
  linux-image-4.10.0-25-generic
0 upgraded, 1 newly installed, 1 to remove and 28 not upgraded.
Need to get 19.0 MB of archives.
After this operation, 68.5 MB of additional disk space will be used.
Do you want to continue? [Y/n]

[dann frazier (dannf)]

Sorry, PEBKAC. Looks like the system I was on had both zesty-proposed & xenial in the sources.list, so the hwe-edge metapackage was trying to install the *zesty-proposed* deb. But, since zesty wasn't in the sources.list, there was no new-enough flash-kernel to install.