Dear lintian maintainers,

While preparing the knot 3.0.2-2 release, `lintian -i -EvIL -pedantic
../knot_3.0.2-2_amd64.changes` reports:
...
X: knot: maintainer-script-supports-ancient-package-version postinst:14 2.5.0-1 (2017-06-07 < 2017-06-18)
N:
I: maintainer-script-supports-ancient-package-version
N:
N:   The maintainer script appears to detect the specified version which
N:   was prepared prior to the release of oldstable.
N:
N:   Please remove the code/check for this version as such upgrades (etc.)
N:   are unsupported.
N:
N:   Severity: info
N:
N:   Check: scripts
N:
N:   This tag is experimental.

2.5.0-1 is indeed an ancient package version. But in contrast to the
information from lintian, it was released after oldstable (currently
stretch), that includes 2.4.0-3+deb9u1:

knot       | 1.6.0-1+deb8u1 | oldoldstable            | source, amd64, armel, armhf, i386
knot       | 2.4.0-3+deb9u1 | oldstable               | source, amd64, arm64, armel, armhf, i386, mips, mips64el, mipsel, ppc64el, s390x
knot       | 2.4.0-3+deb9u1 | oldstable-debug         | source
knot       | 2.7.6-2~bpo9+1 | stretch-backports       | source, amd64, arm64, armel, armhf, i386, mips, mips64el, mipsel, ppc64el, s390x
knot       | 2.7.6-2~bpo9+1 | stretch-backports-debug | source
knot       | 2.7.6-2        | stable                  | source, amd64, arm64, armel, armhf, i386, mips, mips64el, mipsel, ppc64el, s390x
knot       | 2.9.6-1        | testing                 | source, amd64, arm64, armel, armhf, i386, mips64el, mipsel, ppc64el, s390x
knot       | 2.9.6-1        | unstable                | source, amd64, arm64, armel, armhf, i386, mips64el, mipsel, ppc64el, s390x
knot       | 2.9.6-1        | unstable-debug          | source
knot       | 3.0.2-1        | experimental            | source, amd64, arm64, armhf, i386, mips64el, mipsel, ppc64el, s390x
knot       | 3.0.2-1        | experimental-debug      | source

Cheers,