Re: AC_CHECK_PROG is incompatible with alias

[Sylvain Tricot]

>configure:
>checking for hhc... (cached) yes

>make:
>cd tdg/en/html && hhc index.hhp
>/bin/sh: line 1: hhc: command not found


I think there is no problem with 'alias'.
The problem is "(cached)".
"cache files" mechanism is unreliable.
I don't understand why/when/how cache test operates.
But it sometime operates even if "-C" option isn't explicitly used :(.

For example,  "configure  -C" is used with the command "rm configure &&
make" or "touch configure.ac && make"
(HOW TO DISABLE "-C" OPTION  ?) :


$ rm configure && make
cd . && /bin/sh /cygdrive/d/ST/dev/test_prog/missing --run autoconf
/bin/sh ./config.status --recheck
running /bin/sh ./configure  -C  --no-create --no-recursion
configure: loading cache config.cache
checking for a BSD-compatible install... (cached) /usr/bin/install -c
checking whether build environment is sane... yes
checking for gawk... (cached) gawk
checking whether make sets $(MAKE)... (cached) yes
checking for hhc... (cached) hhc
checking for hhc... (cached) /usr/local/bin/hhc
configure: creating ./config.status
 /bin/sh ./config.status
config.status: creating Makefile
make[1]: Entering directory `/cygdrive/d/ST/dev/test_prog'
echo "HHC=hhc  HHC_PATH=/usr/local/bin/hhc";
HHC=hhc  HHC_PATH=/usr/local/bin/hhc
test -n "hhc" && hhc index.hhp
/bin/sh: line 1: hhc: command not found
make[1]: *** [test_prog.chm] Error 127
make[1]: Leaving directory `/cygdrive/d/ST/dev/test_prog'
make: *** [all-recursive] Error 1


# configure.ac for test_prog
# Process this file with autoconf to produce a configure script.
AC_INIT([test_prog],[0.0])
AC_CONFIG_SRCDIR([index.hhp])
AM_INIT_AUTOMAKE
AC_EXEEXT
AC_CHECK_PROG([HHC],[hhc],[hhc],[no])
AC_PATH_PROG([HHC_PATH],[hhc])
AC_CONFIG_FILES([Makefile])
AC_OUTPUT