Subject: bug#54020: Impossible to pass `-no-suppress` to `libtool` via automake files

From: Damian Szuberski <[email-masked]>
Date: Tue, 15 Feb 2022 23:03:02 +0100

Dear automake developers!

A standard `libtool` invocation line generated by automake looks like:
```
LTCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
        $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) \
        $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
        $(AM_CFLAGS) $(CFLAGS)
```
Sometimes files compiled using the method above make the compiler emit
errors. Those errors are suppressed by default which makes troubleshooting
impossible. `libtool` has a command line option, `-no-suppress` which can
be used to make the compiler verbose. Unfortunately, there is no way to
inject that option since `libtool` demands that it comes after
`--mode=compile`. `AM_LIBTOOLFLAGS` nor `LIBTOOLFLAGS` cannot be used for
that purpose since "it is too early", according to `libtool`'s command line
parser. It is somewhat possible to use `AM_CFLAGS` for that purpose but
then it breaks modes other than `--mode=compile`.

Is there any way to make libtool more verbose?
Thanks in advance!

Software used:
```
autoconf (GNU Autoconf) 2.71
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+/Autoconf: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>, <
https://gnu.org/licenses/exceptions.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David J. MacKenzie and Akim Demaille.
automake (GNU automake) 1.16.5
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv2+: GNU GPL version 2 or later <
https://gnu.org/licenses/gpl-2.0.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Tom Tromey <[email-masked]>
       and Alexandre Duret-Lutz <[email-masked]>.
```

-- 
Damian Szuberski