Excellent! :-) Closing this.

Hi Malte,

thanks for your help. You were right, Bison and Flex were not installed
correctly, and after the change in the code you explained here
http://issues.fast-downward.org/issue241 everything is working now.

Thanks, Simon

@Simon: did these comments help you set VAL up? If not, what is the error
message you now get?


Here's what I did in our codebase to reduce flex-/bison-related issues in the
future:

1. To make VAL's dependencies on flex and bison clearer, I've removed the
   (unused) version of FlexLexer.h from the VAL directory and updated the
   Makefile so that it doesn't complain about the missing file.

2. I've also updated the dependencies and made "make clean" and "make
   distclean" behave in the same way as in the main Fast Downward codebase.

3. Finally, there should now be a more meaningful error message when flex
   and/or bison are not installed.

@Simon: Are you actually using the version of VAL that is included with Fast
Downward, or are you using the version that is available for download from the
VAL website at the University of Strathclyde?

From the directory name you mention, it looks like you're using the original VAL
version? In that case, you'd have to contact the people in Strathclyde, as we
have nothing to do with VAL -- we just repackage and include it within Fast
Downward for convenience. But we're not involved in its development in any way.

Thanks for the report, Simon!

Have you installed the flex and bison packages?

On Ubuntu:
$ sudo apt-get install flex bison

They are needed for VAL; see
http://www.fast-downward.org/ObtainingAndRunningFastDownward#Dependencies

The FlexLexer.h files are included by the code with
    #include <FlexLexer.h>
rather than
    #include "FlexLexer.h"
which means that g++ will look for them on the system header path, not the
current directory. If installing flex and/or bison resolves the problem from
you, we should probably remove the (unnecessary) FlexLexer.h file from the VAL
directory. Also, we should probably give a more meaningful error message when
flex and/or bison are not installed.

Once you're sure you have flex and bison installed, please try (in the VAL
directory)
$ make clean
$ rm -f FlexLexer.h
$ rm -f lex.yy.cc
$ touch FlexLexer.h  ## needed because of a Makefile bug
$ make

If this still doesn't work, I'd be interested in the complete output of make as
well as the output of

$ dpkg -L flex
$ dpkg -L bison

I use g++4.6.

/Val-4.2.08 # make
g++  -g -Wall -Werror -iquote -I. -ansi -Wall -c pddl+.cpp -o pddl+.o
In file included from pddl+.yacc:1519:0:
lex.yy.cc:312:23: fatal error: FlexLexer.h: No such file or directory
compilation terminated.
make: *** [pddl+.o] Error 1

Even though the error message says something else, the file FlexLexer.h is in
the directory. 

Thanks, Simon