ELFTC_VCSID is not defined on Cygwin. Easy fix is in the attached patch based on our local source.
FYI we use this library as part of the support tooling for the RTEMS real-time operating system. We have it as part of the rtems-tools repository (https://gitlab.rtems.org/rtems/tools/rtems-tools).
The Cygwin-related change was added in [r4041], thanks!
Related
Commit: [r4041]