Set the minimum required version of CMake high enough to avoid the
warning for CMAKE_LEGACY_CYGWIN_WIN32. The warning appears on stderr
and breaks the expected output matching.
In CMakeDetermineCompilerABI we use try_compile with the COPY_FILE
option to get a copy of the compiled binary used to detect the ABI
information. We already tolerate the case when compilation fails.
However, when compilation appears to succeed but does not produce the
expected executable the try_compile command immediately reports an error
because the COPY_FILE fails.
Tolerate COPY_FILE failure without stopping the overall configuration
process by using the try_compile COPY_FILE_ERROR option to capture the
error message. Log the full error to CMakeError.log and simply report
failure to detect the ABI as if compilation had failed.
Teach the RunCMake.Configure test to cover this case and verify that the
messages show up as expected both in stdout and in CMakeError.log.
When CMake reports failure to configure a project, especially when the
toolchain does not initialize properly, the true reason may be clear
from reading the CMakeFiles/CMake(Output|Error).log files. Advise users
to look at these files if they exist when configuration fails.
Add RunCMake.Configure test to check that the log files are mentioned
when configuration fails.
Brad King