Installation issue: gromacs on Neoverse V2 with/without SVE

[dslarm]

Steps to reproduce the issue

$ spack spec -I gromacs +sve
==> Error: Spack concretizer internal error. Please submit a bug report and include the command, environment if applicable and the following error message.
    gromacs+sve is unsatisfiable

Error message

Error message

spack spec -l gromacs +sve

==> Error: Spack concretizer internal error. Please submit a bug report and include the command, environment if applicable and the following error message.
    gromacs+sve is unsatisfiable

Information on your system

Neoverse V2, Rocky 9.
The default gromacs will build - but it won't add SVE as a variant - and so it won't allow it to be disabled, or enabled, without triggering internal spack issue. I'd expect both options to be there (FWIW - I intend to benchmark to help figure out if this should be default on, or default off).

* **Spack:** 0.22.0.dev0 (f7afd67a266be82d426ce3a6d80e7a7c7500d122)
* **Python:** 3.10.12
* **Platform:** linux-ubuntu22.04-neoverse_v2
* **Concretizer:** clingo

Additional information

@danielahlin @eirrgang @junghans

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have run spack maintainers <name-of-the-package> and @mentioned any maintainers
• I have uploaded the build log and environment files
• I have searched the issues of this repo and believe this is not a duplicate