ci: name the bintest build in ci/gcc-clang - #7140

build_config/ci/gcc-clang.rb defines three builds, and two of them carry a
name. The middle one is written as MRuby::Build.new do |conf|, so
MRuby::Build#initialize gives it the default host, and every line CI prints
for it reads >>> Test host <<<.

That name says nothing about the build. What separates it from its two siblings
is that it is the only one in the file that calls enable_bintest, and the
only one that adds mruby-bin-debugger back after the full-core gembox
leaves it out. This names it bintest after that coverage, so the CI log and
the build directory both say which of the three is speaking.

-MRuby::Build.new do |conf|
+MRuby::Build.new('bintest') do |conf|

Why the host name is free to give up here

host is load bearing elsewhere, so it is worth spelling out that no part of
it applies to this file.

• MRuby::Build#mrbcfile falls back to the mrbc of a host target only for
  a build that is not itself host. All three builds here are MRuby::Build
  rather than MRuby::CrossBuild, and each pulls mruby-bin-mrbc in through
  full-core, so every one of them already has its own.
• install_prefix sends a non host build to <prefix>/mruby/<name>, and
  define_installer_if_needed defines an installer into MRUBY_ROOT/bin only
  when host? answers true. Both run under rake install.
• rake clean removes mrbtest from MRUBY_ROOT/bin for the host target.

The workflows that read this config run rake -m test:run:serial
(build.yml) and rake test (coverage.yml). Neither installs nor cleans, and
run_test and run_bintest reach the binaries through build_dir and the
BUILD_DIR environment variable rather than through bin/, so none of the
above is on the path CI takes.

The one real cost is for a developer who points MRUBY_CONFIG at this config
by hand: the bin/ entries stop appearing, because only a host build
installs them. build_config/default.rb is the config for that use, and this
file exists to be read by the two workflows above.

build_config/ci/msvc.rb is left alone. It holds a single build, so there is no
sibling for a name to tell it apart from, and the default reads fine there.

Verification

MRUBY_CONFIG=ci/gcc-clang rake -m test on Linux with gcc:

The bintest run is the one the rename could have broken, since it resolves
mrdb and the other binaries at run time; it stays green.

Summary by CodeRabbit

• Chores
  • Explicitly named the binary test build configuration for clearer build identification.