Re: libgpiod 2.2 installation on RaspberryPi 4

[Kent Gibson <warthog618@gmail.com>]

On Fri, Nov 01, 2024 at 03:24:42PM +0100, Le Chaudron Nautique wrote:
>
> Le 01/11/2024 à 06:24, Kent Gibson a écrit :
> > On Thu, Oct 31, 2024 at 03:17:32PM +0100, Le Chaudron Nautique wrote:
> > > Le 31/10/2024 à 03:08, Kent Gibson a écrit :
> > > > On Wed, Oct 30, 2024 at 09:59:05PM +0100, Le Chaudron Nautique wrote:
> > > > > Hello,
> > > > >
> > > > Here is what I get using that tarball and:
> > > >
> > > > ./autogen.sh --prefix=/usr/local --enable-examples
> > > > make
> > > > sudo make install
> > > >
> > > > pi@pi4:~/libgpiod-2.2 $ ls -l /usr/local/lib
> > > > total 372
> > > > -rw-r--r-- 1 root root 239480 Oct 31 09:40 libgpiod.a
> > > > -rwxr-xr-x 1 root root    946 Oct 31 09:40 libgpiod.la
> > > > lrwxrwxrwx 1 root root     17 Oct 31 09:40 libgpiod.so -> libgpiod.so.3.1.1
> > > > lrwxrwxrwx 1 root root     17 Oct 31 09:40 libgpiod.so.3 -> libgpiod.so.3.1.1
> > > > -rwxr-xr-x 1 root root 155480 Oct 31 09:40 libgpiod.so.3.1.1
> > > > drwxr-xr-x 2 root root   4096 Oct 31 09:40 pkgconfig
> > > > drwxr-xr-x 4 root root   4096 Jan 13  2024 python3.11
> > > >
> > > > pi@pi4:~/libgpiod-2.2 $ ldd examples/.libs/get_chip_info
> > > > 	linux-vdso.so.1 (0x0000007f9e276000)
> > > > 	libgpiod.so.3 => /usr/local/lib/libgpiod.so.3 (0x0000007f9e1e0000)
> > > > 	libc.so.6 => /lib/aarch64-linux-gnu/libc.so.6 (0x0000007f9e030000)
> > > > 	/lib/ld-linux-aarch64.so.1 (0x0000007f9e239000)
> > > >
> > > > pi@pi4:~/libgpiod-2.2 $ examples/get_chip_info
> > > > gpiochip0 [pinctrl-bcm2711] (58 lines)
> > > >
> > > > What do you get?
> > > I didn't add the --enable-examples, I took the code from git and put it in
> > > my test file/directory.
> > Adding the --enable-examples is just a convenient way to get the
> > examples built.  Building it manually is fine too.
> >
> > > vanvan@lcntest-stable:~/prog/userspace $ ldd prog
> > >      linux-vdso.so.1 (0x0000007fa851e000)
> > >      libgpiod.so.3 => not found
> > >      libc.so.6 => /lib/aarch64-linux-gnu/libc.so.6 (0x0000007fa8300000)
> > >      /lib/ld-linux-aarch64.so.1 (0x0000007fa84e1000)
> > >
> > > Should I look at/capture the autogen logs to see if something is amiss ?
> > >
> > No, the issue is ld not locating the library in /usr/local/lib for some reason.
> >
> > What does
> >
> > $ ldconfig -p | grep libgpiod
> >
> > show?
> >
> > I get:
> >
> > pi@pi4:~/libgpiod-2.2 $ ldconfig -p | grep libgpiod
> > 	libgpiodcxx.so.1 (libc6,AArch64) => /lib/aarch64-linux-gnu/libgpiodcxx.so.1
> > 	libgpiod.so.3 (libc6,AArch64) => /usr/local/lib/libgpiod.so.3
> > 	libgpiod.so.2 (libc6,AArch64) => /lib/aarch64-linux-gnu/libgpiod.so.2
> > 	libgpiod.so (libc6,AArch64) => /usr/local/lib/libgpiod.so
>
> I get only  :
>
> $ ldconfig -p | grep libgpiod
>     libgpiodcxx.so.1 (libc6,AArch64) =>
> /lib/aarch64-linux-gnu/libgpiodcxx.so.1
>     libgpiod.so.2 (libc6,AArch64) => /lib/aarch64-linux-gnu/libgpiod.so.2
>
> But after running
>
> $sudo ldconfig
>
> I can see libgpiod.so.3 and the program runs  without problem anymore.
>
>
> $ ldconfig -p | grep libgpiod
>     libgpiodcxx.so.1 (libc6,AArch64) =>
> /lib/aarch64-linux-gnu/libgpiodcxx.so.1
>     libgpiod.so.3 (libc6,AArch64) => /usr/local/lib/libgpiod.so.3
>     libgpiod.so.2 (libc6,AArch64) => /lib/aarch64-linux-gnu/libgpiod.so.2
>     libgpiod.so (libc6,AArch64) => /usr/local/lib/libgpiod.so
>
> $ ldd prog
>     linux-vdso.so.1 (0x0000007f957eb000)
>     libgpiod.so.3 => /usr/local/lib/libgpiod.so.3 (0x0000007f95740000)
>     libc.so.6 => /lib/aarch64-linux-gnu/libc.so.6 (0x0000007f95590000)
>     /lib/ld-linux-aarch64.so.1 (0x0000007f957a0000)
>
>
> Thanks.
>
>

As the reply didn't go to the list, just letting you know that the problem
was the ld.so.cache not being rebuilt when libgpiod is installed by
'sudo make install'.

Not sure of this is Pi specific, or v2.2 specific, but I suspect at
least one other Pi user has seen the same thing.

The last thing the install (installing into /usr/local) with libtool does is:

libtool: finish: PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/sbin" ldconfig -n /usr/local/lib

which, IIUC, updates that directory in the cache and any symlinks it
contains, but it doesn't rebuild the cache.  So it will work fine if you
are updating but not on the first install??

The workaround is to 'sudo ldconfig' after the install to rebuild the
cache.  But I was expecting that autoconf/libtool would sort this out.

Cheers,
Kent.