I tried boot Lubuntu groovy [20200710] on dc7900
hp dc7900 (c2d-e8400, 4gb, intel 4 series integrated i915)
It failed with this issue as expected :(
HOWEVER in comment #29 I'd grabbed a random thumb-drive for a test boot, which was (redS) Xubuntu groovy ISO dated 2020-07-01 which booted normally (and is running on dc7700 to validate date from /etc/apt/sources.list), but that thumb-drive (Xubuntu DAILY [20200701]) won't boot on dc7900 either !!
I grabbed another few random thumb-drives (debian buster lxqt & knoppix 8.6 also based on buster, and ubuntu 20.04 [possibly a late RC]) which booted normally
I tried boot Lubuntu groovy [20200710] on dc7900
hp dc7900 (c2d-e8400, 4gb, intel 4 series integrated i915)
It failed with this issue as expected :(
HOWEVER in comment #29 I'd grabbed a random thumb-drive for a test boot, which was (redS) Xubuntu groovy ISO dated 2020-07-01 which booted normally (and is running on dc7700 to validate date from /etc/apt/ sources. list), but that thumb-drive (Xubuntu DAILY [20200701]) won't boot on dc7900 either !!
I grabbed another few random thumb-drives (debian buster lxqt & knoppix 8.6 also based on buster, and ubuntu 20.04 [possibly a late RC]) which booted normally