cc1: fatal error: ovis_json_lexer.c: No such file or directory

[Vanessasaurus]

Hiya! I want to open this mostly for visibility - I was following the instructions here and ran into this issue:

vis_json_parser.y:58.1-7: warning: POSIX Yacc does not support %define [-Wyacc]
   58 | %define api.pure full
      | ^~~~~~~
make  all-recursive
make[5]: Entering directory '/ovis/lib/src/ovis_json'
make[6]: Entering directory '/ovis/lib/src/ovis_json'
  CC       ovis_json_test-ovis_json_test.o
  CC       ovis_json.lo
: -o ovis_json_lexer.c ovis_json_lexer.l
  CC       ovis_json_lexer.lo
cc1: fatal error: ovis_json_lexer.c: No such file or directory

Looking at this file it looks like we need something called $(LEX) to generate that file. In retrospect I see it here but I didn't see it here so wanted to open an issue if others stumble on this they will easily find the solution. The solution is to:

$ apt-get install -y flex

And then it will build! And maybe the getting started guide could include that too. Thank you!

[Christopher J. Morrone]

Yes, there was probably a warning the "configure" output, but AC_PROG_LEX doesn't error out when a lexer isn't found. We should probably add an autoconf test that checks if it is possible to execute "$LEX --version", and throw an error if it isn't.