b052497701
VS2026 ships on the prerelease channel; vswhere omits it unless -prerelease is given. Without it _find_msbuild_via_vswhere returned nothing, so the path fallback picked an incomplete (x86)\Microsoft Visual Studio\18\BuildTools install (MSBuild present but no VC v180 targets) -> MSB4019 on hosts that have VS2026 IDE but not BuildTools. -prerelease is harmless on the CI VM (BuildTools is found regardless). Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>