error 1.5.0-dev build about ddcutil HOT 2 CLOSED

I fixed the missing errno.h problem and pushed the change to github. Thank you.

Do I understand correctly that the first run of .configure did not detect that libjansson-dev was not installed? Autoconf macro PKG_CHECK_MODULE() looks for file jansson.pc installed by the development package and terminates configure execution if the file is not found.

autogen is a convenience wrapper around autoreconf and configure. autoreconf is itself a wrapper. From the autotools doc:
"autoreconf runs autoconf, autoheader, aclocal, automake, libtoolize, and autopoint (when appropriate) repeatedly to update the GNU Build System in the specified directories and their subdirectories."

If you look at the output of autogen vs configure, you'll see output at the start before the output from configure.

Generally speaking, after running autogen once, the only time it needs to be run again is if there a change to configure.ac or one of the Makefile.am files in the source tree.

from ddcutil.

run ./autogen.sh was after install libjansson-dev.
don't forget add libjansson-dev to depences

from ddcutil.