Steps to reproduce

Refers to #48574 (comment) The error is encoded in a xfailing unit test.

@JohnGouwar reported in DM that the potential source of the issue is likely the topological order used in the splicing implementation, which is unstable. When the unit test fails:

[splice-h@1.0.2/kdgv3sodjrdmvaejldwcl4vcjc4isoei, splice-t@1.0/jpufqbulg2an2jh3olo2dpzcfbgfeir2, splice-z@1.0.2/ry4yllp5frzp35bcxzxn64wjs2aahyuw, splice-z@1.0.1/76rrwplin42mcyv4xeued5fwsz4t2d7r, splice-h@1.0.0/ujzmt4yad7bfs6s5sr6puherehfegtrf, splice-z@1.0.0/titp6gw3kqfej76bqzyvum3sinjxv2lu]

when the unit test passes:

[splice-t@1.0/jpufqbulg2an2jh3olo2dpzcfbgfeir2, splice-z@1.0.2/ry4yllp5frzp35bcxzxn64wjs2aahyuw, splice-h@1.0.2/kdgv3sodjrdmvaejldwcl4vcjc4isoei, splice-h@1.0.0/ujzmt4yad7bfs6s5sr6puherehfegtrf, splice-z@1.0.1/76rrwplin42mcyv4xeued5fwsz4t2d7r, splice-z@1.0.0/titp6gw3kqfej76bqzyvum3sinjxv2lu]

Error message

No error, but instabilities in spliced specs

Information on your system

• Spack: 0.24.0.dev0 (59a7195)
• Python: 3.13.0
• Platform: linux-ubuntu20.04-icelake

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output