Hi. The relevant paragraph in Policy is this one:
If build-time dependencies are specified, it must be possible to build the package and produce working binaries on a system with only essential and build-essential packages installed and also those required to satisfy the build-time relationships (including any implied relationships). Note that this is a MUST requirement in policy. Moreover, this policy 4.2 item is a release goal: Packages must list any packages they require to build beyond those that are "build-essential" in the appropriate Build-Depends: fields. Ref: 4.2 Source: https://release.debian.org/testing/rc_policy.txt So if you want to downgrade the bug, go ahead, but as explained, it would be wrong. Thanks.