Summary

mongodl infers the download target from the host operating system alone. On Ubuntu 26.04 hosts it always selects ubuntu2404, so downloads of server releases that publish native ubuntu2604 archives use ubuntu2404 binaries instead. We want mongodl to use the ubuntu2604 target for versions that publish it, and keep ubuntu2404 for versions that never will.

Recent server releases publish ubuntu2604 archives (for example 9.0.4). Server build support for Ubuntu 26.04 landed in SERVER-131625. Older releases will never receive ubuntu2604 builds, and they are the versions the current ubuntu2404 mapping caters to.

Motivation

Who is the affected end user?

Driver engineers and CI users who download server binaries with mongodl on Ubuntu 26.04 hosts, including GitHub ubuntu-latest runners.

How does this affect the end user?

They get ubuntu2404 binaries on a 26.04 host even when native ubuntu2604 archives exist. Nobody is blocked: ubuntu2404 binaries run on 26.04.

How likely is it that this problem or use case will occur?

Main path for 26.04 hosts.

If the problem does occur, what are the consequences and how severe are they?

Minor: binaries built for an older distribution than the host runs. No functional failure expected.

Is this issue urgent?

No required timeline.

Is this ticket required by a downstream team?

No.

Is this ticket only for tests?

No, it changes mongodl download behavior.

Acceptance Criteria

• On an Ubuntu 26.04 host, mongodl downloads the ubuntu2604 archive for a requested version that publishes one.
• Versions without ubuntu2604 archives keep resolving to ubuntu2404 on 26.04 hosts.
• The mapping comment in mongodl.py cites this ticket instead of DRIVERS-3728.