The packaging-rpm Evergreen task (packaging build variant) on the cxx-driver waterfall has been failing since ~late August 2026.

*Immediate trigger:* the image no longer ships the fedora-40-aarch64 mock config the task selected, so mock fails at chroot init.

*Deeper problem:* every replacement mock config tried so far fails the same way inside rpmbuild. The task FetchContent-downloads MongoDB C Driver 2.5.4 (system mongo-c-driver-devel on EPEL 10 is only 2.5.2, below the C++ driver's 2.5.4 minimum), and CMake configure of that downloaded C driver fails with:

CMake Error at redhat-linux-build/_deps/mongo-c-driver-src/src/libmongoc/CMakeLists.txt:803 (message):
  ENABLE_SRV is "ON", but we were unable to find a name resolution library

This reproduces under both fedora-43-aarch64 and centos-stream+epel-10-aarch64 mock configs. It is not a missing glibc-devel: the el10 chroot had glibc-devel-2.39-141.el10.aarch64 installed and the check still failed. Enabling network in the mock chroot did not help either.

*Patch builds tried (2026-09-26, branch signoff-20260926-fix-packaging of a local checkout, base 87b0d68300):*

• 6ab7c41c4cd9590007dda064 — fedora-43-aarch64 mock config
• 6ab7ca9bed25460007344e77 — network enabled in mock chroot
• 6ab7d032dd15ba000758dd5d — centos-stream+epel-10-aarch64 mock config (mirrors mongo-c-driver's own RPM packaging target); local commits 52ec43a5d3, ea34330e85, c25a682b4c

All three failed at the same ENABLE_SRV ... unable to find a name resolution library configure step (or at mock init).

*Possible directions:*

• Investigate why the C driver's resolver-library probe (src/libmongoc/CMakeLists.txt ~line 803) fails under CentOS Stream 10 / Fedora chroots despite glibc-devel being present (res_nsearch has lived in libc since glibc 2.34).
• Or configure the FetchContent'd C driver with -DENABLE_SRV=OFF in the RPM build (if dropping SRV support in the package is acceptable).
• Or ship a C driver >= 2.5.4 in EPEL 10 / Fedora and build against the system C driver instead of FetchContent.