It will also ensure that ldconfig is invoked during install and removal when it finds shared libraries. Since debhelper 9.20151004, this is done via a dpkg trigger. In older versions of debhelper, dh_makeshlibs would generate a maintainer script for this purpose.
Since debhelper 12.3, dh_makeshlibs will by default add an additional udeb line for udebs in the shlibs file, when the udeb has the same name as the deb followed by a ``-udeb'' suffix (e.g. if the deb is called ``libfoo1'', then debhelper will auto-detect the udeb if it is named ``libfoo1-udeb''). Please use the --add-udeb and --no-add-udeb options below when this auto-detection is insufficient.
If you previously used --add-udeb and is considering to migrate to using the auto-detection new auto-detection feature in 12.3, then please remember to test that the resulting DEBIAN/shlibs files are as expected. There are some known corner cases, where the auto-detection is insufficient. These include when the udeb contains library files from multiple regular deb packages or when the packages do not follow the expected naming convention.
Note in compat levels 9 and earlier, this file was installed by dh_installdeb(1) rather than dh_makeshlibs.
In compat 12 and later, dh_makeshlibs defaults to -VUpstream-Version. In compat 11 and earlier the default behaved like -VNone.
The dh_makeshlibs tool can generate dependencies in three variants:
This is a conservative setting that always ensures that other packages' shared library dependencies are at least as tight as they need to be (unless the library is prone to changing ABI without updating the upstream version number).
The flip side is that packages might end up with dependencies that are too tight in some cases (note a symbols file can mitigate this issue). This is often of minor temporary inconvenience and usually a lot better than the fall out caused by forgetting to bump the dependency information.
This explicit form was added in debhelper/11.3. In previous versions, a -V without any dependency information was used instead (and that form still works)
This form is generally unsafe with the only exception being if upstream does not extend the ABI in any way. However, most upstreams improve their interfaces over time and packagers are recommended to use -VUpstream-Version (or one of the other forms of -Vdependencies).
Alternatively, this may be sufficient if (and only if) the package uses symbol versioning (see dpkg-gensymbols(1)) and does not build any udeb packages. Note that symbols are not supported for udeb packages, which solely relies on shlibs for dependency handling.
Note that debhelper will use the value as it is with no sanity checking or modification. In rare special cases, this is needed to generate a dependency on a different package than the one containing the library.
When choosing a value for this option, please keep mind that if the package provides a symbols file, then that this is generally preferred over the shlibs file for regular .deb packages. See dpkg-shlibdeps(1) for more information on this topic.
This option is only useful for special cases such as when debhelper cannot auto-detect package name of the udeb package, when the udeb will contain libraries from multiple deb packages, or when the udeb contains libraries not present in the deb package.
This may be useful in case you do not want a shlibs file at all for the udeb because no package will depend on it. E.g. because adding a udeb package for the library was ``overkill'' and the library is embedded in a different udeb package.