Author(s): The Ciao Development Team.

If you experience any problem downloading, installing, or using Ciao you can send a message to <>. Please be as informative as possible in your messages, so that we can reproduce the bug.

  • For installation problems we typically need to have the installation method, the version and patch number of the Ciao package (e.g., the name of the file downloaded), the output produced by the installation process (you can capture it by redirecting the output into a file or cutting and pasting with the mouse), and the exact version of the Operating System you are using (as well as the C compiler, if you took a source distribution).

  • For problems during use we also need the Ciao and OS versions and, if possible, a small example of code which we can run to reproduce the bug.

This is a list of common issues and their solutions:

  • Problem: Compilation errors appear when trying a new installation/compilation after the previous one was aborted (e.g., because of errors) or after a source upgrade from the development version.

    Possible reason and solution: It is a good idea to clean up any leftovers from the previous compilation. It the worst case, if none of the clean commands work, try ./ emergency-clean.

  • Problem: In Windows (under Cygwin or MSYS2), many programs (including emacs and ciao) exit with error messages like:

    Doing vfork: resource temporarily unavailable

    Possible reason and solution:

    Cygwin needs a special memory layout to implement the fork semantics in Win32 ( A workaround this problem is using the rebaseall command, which relocates all Cygwin DLLs into a layout that avoids collisions:

    • 1. End all cygwin processes.
    • 2. Run /bin/rebaseall from c:\cygwin\bin\ash (probably as administrator)