dh_makeshlibs1

Usage

Overview

dh_makeshlibs is a debhelper program that automatically scans for shared libraries, and generates a shlibs file for the libraries it finds.

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 are considering to migrate to using the 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.

Files

debian/package.shlibs

Installs this file, if present, into the package as DEBIAN/shlibs. If omitted, debhelper will generate a shlibs file automatically if it detects any libraries.

Note in compat levels 9 and earlier, this file was installed by dh_installdeb(1) rather than dh_makeshlibs.

debian/package.symbols

debian/package.symbols.arch

These symbols files, if present, are passed to dpkg-gensymbols(1) to be processed and installed. Use the arch specific names if you need to provide different symbols files for different architectures.

Options

-mmajor, --major=major

Instead of trying to guess the major number of the library with objdump, use the major number specified after the -m parameter. This is much less useful than it used to be, back in the bad old days when this program looked at library filenames rather than using objdump.

-V, -Vdependencies

--version-info, --version-info=dependencies

If a shlibs file is generated by this program, this option controls what version will be used in the dependency relation.

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:

-VUpstream-Version

The dependency will be "packagename (>= packageversion)". Note that Upstream-Version is case-sensitive and must be written exactly as shown here.

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)

-VNone

The dependency will be "packagename". Note that None is case-sensitive and must be written exactly as shown here.

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.

-Vpackage-relation

In this case, the value passed to -V will be used as a dependency relation. The package-relation should generally be of the form "some-package-name (>= some-package-version)". Remember to include the package name.

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.

-n, --no-scripts

Do not add the "ldconfig" trigger even if it seems like the package might need it. The option is called --no-scripts for historical reasons as dh_makeshlibs would previously generate maintainer scripts that called ldconfig.

-Xitem, --exclude=item

Exclude files that contain item anywhere in their filename or directory from being treated as shared libraries.

--add-udeb=udeb

Create an additional line for udebs in the shlibs file and use udeb as the package name for udebs to depend on instead of the regular library package.

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.

--no-add-udeb

Do not add any udeb lines to the shlibs file. This can be used to disable the default auto-detection of udebs.

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.

-- params

Pass params to dpkg-gensymbols(1).

Examples

dh_makeshlibs -VNone

Assuming this is a package named libfoobar1, generates a shlibs file that looks something like:
libfoobar 1 libfoobar1

dh_makeshlibs -VUpstream-Version

Assuming the current version of the package is 1.1-3, generates a shlibs file that looks something like:
libfoobar 1 libfoobar1 (>= 1.1)

dh_makeshlibs -V 'libfoobar1 (>= 1.0)'

Generates a shlibs file that looks something like:
libfoobar 1 libfoobar1 (>= 1.0)