What does it take for extconf.rb to recognize readline.h?
extconf.rb seems blind to whatever I tell it.
Here, extconf.rb does not see readline.h:
cd ext/readline
% ../../ruby extconf.rb
checking for tgetnum() in -lncurses... no
checking for tgetnum() in -ltermcap... yes
checking for readline/readline.h... no
checking for editline/readline.h... no
Here, it is plainly visible in the directories it should be looking:
% ../../ruby -r mkmf -e 'p Config::CONFIG["CPPFLAGS"]'
"-I/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/include/readline"
% ../../ruby -r mkmf -e 'p Config::CONFIG["CFLAGS"]'
"-I/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/include/readline"
% ../../ruby -r mkmf -e 'p Config::CONFIG["LDFLAGS"]'
"-L/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/lib"
% ls -alF
/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/include/readline
total 84
drwxrwsr-x 2 jdf jdf 4096 Jan 30 11:03 ./
drwxrwsr-x 3 jdf jdf 4096 Jan 30 11:03 …/
-rw-r–r-- 1 jdf jdf 10207 Jan 30 11:03 history.h
-rw-r–r-- 1 jdf jdf 34354 Jan 30 11:03 readline.h
…
% ls -alF /TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/lib
total 2256
drwxrwsr-x 2 jdf jdf 4096 Jan 30 11:03 ./
drwxrwsr-x 7 jdf jdf 4096 Jan 30 11:03 ../
...
-rw-r--r-- 1 jdf jdf 1053548 Jan 30 11:03 libreadline.a
lrwxrwxrwx 1 jdf jdf 16 Jan 30 11:03 libreadline.so ->
libreadline.so.5
-rw-r–r-- 1 jdf jdf 917076 Jan 30 11:03 libreadline.so.5
Can someone splain why? 
