phases: stop using `repo.set` in `remotephasessummary` The `repository.set` create changectx on the fly, an expensive operation. Using `repo.revs` and a direct rev-num → node-id translation will be significantly faster. This is especially true as we prepare ourself to no longer do the rev-num → node-id transalation there. The speedup is a bit lost in the overall noisyness of the slow phase discovery algorithm, but it save a small amount of time in my benchmark.

{
    "version": 1,
    "project": "mercurial",
    "project_url": "https://mercurial-scm.org/",
    "repo": "..",
    "branches": ["default", "stable"],
    "environment_type": "virtualenv",
    "show_commit_url": "https://www.mercurial-scm.org/repo/hg/rev/",
    "benchmark_dir": "benchmarks",
    "env_dir": "../.asv/env",
    "results_dir": "../.asv/results",
    "html_dir": "../.asv/html"
}