Output error text if cmake failed during triplet var detection

[JackBoosY]

When VCPKG_FORCE_SYSTEM_BINARIES is set and cmake is not installed, the install command will stop and no specific information is printed:

PS F:\vcpkg> .\vcpkg.exe install ctemplate
Computing installation plan...

PS F:\vcpkg>

Output with --debug:

PS F:\vcpkg> .\vcpkg.exe install ctemplate --debug
[DEBUG] Feature flag 'binarycaching' unset
[DEBUG] Feature flag 'manifests' unset
[DEBUG] Feature flag 'compilertracking' unset
[DEBUG] Feature flag 'registries' unset
[DEBUG] Feature flag 'versions' unset
[DEBUG] Failed to open: F:\vcpkg\vcpkg-bundle.json
[DEBUG] Bundle config: readonly=0, usegitregistry=0, embeddedsha=nullopt
[DEBUG] Using builtin-ports: F:\vcpkg\ports
[DEBUG] Using installed-root: F:\vcpkg\installed
[DEBUG] Using buildtrees-root: F:\vcpkg\buildtrees
[DEBUG] Using packages-root: F:\vcpkg\packages
[DEBUG] Using scripts-root: F:\vcpkg\scripts
[DEBUG] Using vcpkg-root: F:\vcpkg
[DEBUG] Using scripts-root: F:\vcpkg\scripts
[DEBUG] Using builtin-registry: F:\vcpkg\versions
[DEBUG] Using downloads-root: F:\vcpkg\downloads
[DEBUG] Default binary cache path is: C:\Users\usr\AppData\Local\vcpkg\archives
Computing installation plan...
[DEBUG] CreateProcessW(cmake -DVCPKG_ROOT_DIR=F:/vcpkg -DPACKAGES_DIR=F:/vcpkg/packages -DBUILDTREES_DIR=F:/vcpkg/buildtrees -D_VCPKG_INSTALLED_DIR=F:/vcpkg/installed -DDOWNLOADS=F:/vcpkg/downloads -DVCPKG_MANIFEST_INSTALL=OFF -P "F:\vcpkg\buildtrees\0.vcpkg_dep_info.cmake")
[DEBUG] 2156: cmd_execute_and_stream_data() returned 2 after     3427 us

[DEBUG] D:\a\_work\1\s\src\vcpkg\cmakevars.cpp(267):
[DEBUG] Time in subprocesses: 3427 us
[DEBUG] Time in parsing JSON: 50160 us
[DEBUG] Time in JSON reader: 28941 us
[DEBUG] Time in filesystem: 15995594 us
[DEBUG] Time in loading ports: 16095057 us
[DEBUG] Exiting after 16.36 s (16243766 us)

Fixed results:

PS F:\vcpkg> .\vcpkg.exe install ctemplate
Computing installation plan...
command:
cmake -DVCPKG_ROOT_DIR=F:/vcpkg -DPACKAGES_DIR=F:/vcpkg/packages -DBUILDTREES_DIR=F:/vcpkg/buildtrees -D_VCPKG_INSTALLED_DIR=F:/vcpkg/installed -DDOWNLOADS=F:/vcpkg/downloads -DVCPKG_MANIFEST_INSTALL=OFF -P "F:\vcpkg\buildtrees\0.vcpkg_dep_info.cmake"
failed with the following results:


PS F:\vcpkg>

[JackBoosY]

Maybe fix microsoft/vcpkg#16216.

[autoantwort]

Without #483 still a very misleading message.

[ras0219-msft]

Agreed that #483 will complete this fix, but we need both.