test programs build failure

[Sven Joachim]

Preparing to update the Debian ncurses packages to the most recent
patchlevel, I hit an error when trying to build the test programs, see
the log at [1].

The Debian build process is a bit convoluted, but basically we build the
libraries with --enable-widec and then configure the test programs
separately to link with the just build libraries.  The reason for that
is mainly that we need to run "make install" in the test directory.

Up to the 20210821 patchlevel this worked, but it broke in the 20210828
patchlevel.  To track down the problem, I compared the corresponding
config.log files (not visible at [1], unfortunately) and the culprit
seems to be that in the 20210828 patchlevel pkg-config support is
disabled, leading to a failure later on because -ltinfo is missing.

In the successful 20210821 build I get:

,----
| configure:7997: checking pkg-config for ncursesw
| configure:8000: result: yes
| configure:8003: checking if the ncursesw package files work
| configure:8336: gcc -o conftest -g -O2 
-ffile-prefix-map=/tmp/ncurses-6.2+20210821=. -fstack-protector-strong -Wformat 
-Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2   
-I/tmp/ncurses-6.2+20210821/obj-wide/include -D_DEFAULT_SOURCE 
-D_XOPEN_SOURCE=600 -L/tmp/ncurses-6.2+20210821/obj-wide/lib -Wl,-z,relro 
-Wl,-z,now conftest.c -lncursesw -ltinfo  >&5
| configure:8339: $? = 0
`----

In the failed 20210828 there is a difference:

,----
| configure:8144: checking pkg-config for ncursesw
| configure:8147: result: yes
| configure:8150: checking if the ncursesw package files work
| configure:8530: gcc -o conftest -g -O2 
-ffile-prefix-map=/tmp/ncurses-6.2+20210828=. -fstack-protector-strong -Wformat 
-Werror=format-security -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 
-L/tmp/ncurses-6.2+20210828/obj-wide/lib -Wl,-z,relro -Wl,-z,now conftest.c 
-lncursesw -ltinfo  >&5
| configure:8519:10: fatal error: curses.h: No such file or directory
| compilation terminated.
| configure:8533: $? = 1
`----

The problem is that -I/tmp/ncurses-6.2+20210828/obj-wide/include is
missing from the gcc commandline, along with a few other options.
Reverting test/aclocal.m4 to version 1.197 (and autoreconfing) fixes
that.

Any ideas?

Cheers,
       Sven


1. https://salsa.debian.org/joachim-guest/ncurses/-/jobs/1885640