message: Improve unsupported toolchain error message
diff: @@ -217,7 +217,12 @@ namespace vcpkg::Build
  if (it != toolset.supported_architectures.end()) return it->name;
  }
  - Checks::exit_with_message(VCPKG_LINE_INFO, "Unsupported toolchain combination %s", target_architecture);
  + Checks::exit_with_message(VCPKG_LINE_INFO,
  + "Unsupported toolchain combination. Target was: %s but supported ones were:\n%s",
  + target_architecture,
  + Strings::join(",", toolset.supported_architectures, [](const ToolsetArchOption& t) {
  + return t.name.c_str();
  + }));
  }
  std::string make_build_env_cmd(const PreBuildInfo& pre_build_info, const Toolset& toolset)
  @@ -520,8 +525,8 @@ namespace vcpkg::Build
  System::cmd_execute_clean(Strings::format(
  R"("%s" x "%s" -o"%s" -y >nul)", seven_zip_exe.u8string(), archive_path.u8string(), pkg_path.u8string()));
  #else
  - System::cmd_execute_clean(Strings::format(
  - R"(unzip -qq "%s" "-d%s")", archive_path.u8string(), pkg_path.u8string()));
  + System::cmd_execute_clean(
  + Strings::format(R"(unzip -qq "%s" "-d%s")", archive_path.u8string(), pkg_path.u8string()));
  #endif
  }
  @@ -537,8 +542,7 @@ namespace vcpkg::Build
  #if defined(_WIN32)
  auto&& seven_zip_exe = paths.get_tool_exe(Tools::SEVEN_ZIP);
  - System::cmd_execute_clean(Strings::format(
  - R"("%s" a "%s" "%s\*" >nul)",
  + System::cmd_execute_clean(Strings::format(R"("%s" a "%s" "%s\*" >nul)",
  seven_zip_exe.u8string(),
  tmp_archive_path.u8string(),
  paths.package_dir(spec).u8string()));
  