Libtool outside autotools: how do I DESTDIR? - makefile

Question

I'm using libtool (version 2.4.6) for creating a simple shared library
under GNU/Linux.
In my specific case, portability is not as important as simplicity: I don't
want to use the whole Autotools suite, nor CMake. I just want a simple
Makefile which can compile a shared library and install it properly.
I've got a couple of variables definitions, which follow the
conventions of GNU Make
prefix ?= /usr/local
exec_prefix ?= $(prefix)
libdir ?= $(exec_prefix)/lib
I want to support an install target, and I believe it should be roughly
like this:
LIBTOOL_LIB := libxyz.la
install: target = $(abspath $(DESTDIR))
install: all
mkdir -p $(target)/$(libdir)
libtool --mode=install install $(LIBTOOL_LIB) $(target)/$(libdir)
libtool --mode=finish $(target)/$(libdir)
If I run make install DESTDIR=./test I get the following message:
mkdir -p /yadayada/src/test//usr/local/lib
libtool --mode=install install libtrullallero.la /yadayada/src/test//usr/local/lib
libtool: install: install .libs/libtrullallero.so.0.0.0 /yadayada/src.so.0.0.0
libtool: install: (cd /yadayada/src.so.0; }; })
libtool: install: (cd /yadayada/src.so; }; })
libtool: install: install .libs/libtrullallero.lai /yadayada/src.la
libtool: install: install .libs/libtrullallero.a /yadayada/src.a
libtool: install: chmod 644 /yadayada/src.a
libtool: install: ranlib /yadayada/src.a
libtool: warning: remember to run 'libtool --finish /usr/local/lib'
libtool --mode=finish /yadayada/src/test//usr/local/lib
libtool: finish: PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/sbin" ldconfig -n /yadayada/src/test//usr/local/lib
----------------------------------------------------------------------
Libraries have been installed in:
/yadayada/src/test//usr/local/lib
If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the '-LLIBDIR'
flag during linking and do at least one of the following:
- add LIBDIR to the 'LD_LIBRARY_PATH' environment variable
during execution
- add LIBDIR to the 'LD_RUN_PATH' environment variable
during linking
- use the '-Wl,-rpath -Wl,LIBDIR' linker flag
- have your system administrator add LIBDIR to '/etc/ld.so.conf'
See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------------------------------------------
I guess I deserve this notification, since I'm installing outside the
regular library path. This is by the way the same message I would get in a
Autotools-based project, should I set a --prefix in some arbitrary path at
./configure.
There are however some weird things:
If I run make install as root (within a container, of course), without
defining DESTDIR, I get the same kind of message. This does not feel
correct: this time I did not deserve it.
With or without DESTDIR, a call to ldconfig makes in my opinion no
sense at this point. And when I'm not running it as root, it should be
also ineffective, yet the program succeeds.
Lurking in the libtool documentation, I've found a
reference to the -inst-prefix-dir option,
which should allow me to have a DESTDIR-like behaviour.
Perhaps this is what I do wrong. However it behaves weirdly!
For starters, it seems to work only if specified at the end of the
--mode=install line. In fact, if I do this:
install: target = $(abspath $(DESTDIR))
install: all
mkdir -p $(target)/$(libdir)
libtool --mode=install install -inst-prefix-dir $(target) $(LIBTOOL_LIB) $(target)/$(libdir)
libtool --mode=finish $(target)/$(libdir)
…I clearly get a messy command line:
libtool: install: install -inst-prefix-dir /yadayada/libtrullallero/test/usr/local/lib/-inst-prefix-dir
install: invalid option -- 'i'
If I move -inst-prefix-dir to the end of the line, I just get another
wrong call to install:
mkdir -p /yadayada/src/libtrullallero/test//usr/local/lib
libtool --mode=install install libtrullallero.la /yadayada/src/libtrullallero/test
libtool: install: install .libs/libtrullallero.so.0.0.0 /yadayada/src/libtrullallero/test/libtrullallero.so.0.0.0
libtool: install: (cd /yadayada/src/libtrullallero/test && { ln -s -f libtrullallero.so.0.0.0 libtrullallero.so.0 || { rm -f libtrullallero.so.0 && ln -s libtrullallero.so.0.0.0 libtrullallero.so.0; }; })
libtool: install: (cd /yadayada/src/libtrullallero/test && { ln -s -f libtrullallero.so.0.0.0 libtrullallero.so || { rm -f libtrullallero.so && ln -s libtrullallero.so.0.0.0 libtrullallero.so; }; })
libtool: install: install .libs/libtrullallero.lai /yadayada/src/libtrullallero/test/libtrullallero.la
libtool: install: install /yadayada/src/libtrullallero/test/lib
install: omitting directory '/yadayada/src/libtrullallero/test//usr/local/lib'
Makefile:22: recipe for target 'install' failed
make: *** [install] Error 1
I must be doing something wrong, but I cannot spot it. Any hint?