lib/imagery: fix missing SONAME

[neteler]

The change implemented in #2269 actually didn't fix the SONAME problem (see issue #2268), at least on Fedora:

# status after PR 2269:
readelf -d /usr/lib64/grass80/lib/libgrass_imagery.so

Dynamic section at offset 0x16860 contains 31 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_gis.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_raster.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_vector.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000001d (RUNPATH)            Library runpath: [/usr/lib64/grass80/lib]
 0x000000000000000c (INIT)               0x5000
 0x000000000000000d (FINI)               0x11e8c
 0x0000000000000019 (INIT_ARRAY)         0x17848
...

==> The SONAME is still missing which means that #2269 did not solve it (tested on Fedora).

With this PR (see e.g. also lib/display/Makefile) the SONAME appears:

readelf -d /home/mneteler/software/grass80/dist.x86_64-pc-linux-gnu/lib/libgrass_imagery.so

Dynamic section at offset 0x14db8 contains 30 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_gis.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_raster.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_vector.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000000e (SONAME)             Library soname: [libgrass_imagery.8.0.so]
 0x000000000000001d (RUNPATH)            Library runpath: [/usr/local/grass80/lib]
 0x000000000000000c (INIT)               0x5000
 0x000000000000000d (FINI)               0x10864
 0x0000000000000019 (INIT_ARRAY)         0x15da0
...

which is a requirement to compile, install and run the GDAL-GRASS driver (https://github.com/OSGeo/gdal-grass).

Can @t0b3 please check if this works on Gentoo as well?

[t0b3]

@neteler thanks for asking. On gentoo this patch has been introduced on top of grass-8.0.1
gentoo/gentoo@9cd5e5a

I since then I get this and output and gdal compiles fine

$ readelf -d /usr/lib64/grass80/lib/libgrass_imagery.so 

Dynamic section at offset 0x14dc8 contains 29 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_gis.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_raster.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_vector.8.0.so]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000000e (SONAME)             Library soname: [libgrass_imagery.8.0.so]
...

also with current master as of now I get

readelf -d /var/tmp/portage/sci-geosciences/grass-9999/image/usr/lib64/grass83/lib/libgrass_imagery.so 

Dynamic section at offset 0x14db8 contains 30 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_gis.8.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_raster.8.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libgrass_vector.8.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000000e (SONAME)             Library soname: [libgrass_imagery.8.3.so]
 0x000000000000001d (RUNPATH)            Library runpath: [/usr/grass83/lib]
...

[t0b3]

I just tested this PR and AFAICT it won't hurt neither. Result is still the same 👍

[nilason]

There is no SONAME involved in Mac dylibs. This PR doesn't make any difference in either direction, so if needed on some platforms I will not object.
It's not obvious to me with a quick look, what part of Vars.make that make it work on Fedora though. On the other hand, quite a few of the other libs are also including this file.