The tag is present in Lintian version 2.113.26. That is the most recent version we know about.
We use semantic versions.
The patch number is a commit step indicator relative to the
release tag in our Git
You can find the detection logic for this version at commit 43a81d7. For merge requests, please use the latest version in the Lintian check files/pkgconfig.
The arch all pkg-config file contains a reference to a multi-arch path.
This can be usually be fixed by moving this file to a multi-arch path.
Another likely cause is using debhelper 9 or newer (thus enabling multi-arch paths by default) on a package without multi-arch support. The usual cure in this case is to update it for multi-arch.
Last but not least, this file could contain a reference to a cross architecture (like for instance an x86_64-linux-gnu pkg-config file referencing an i386-linux-gnu file). In this case the usual cure is to fix this path.