.Dd September 27, 2026
.Dt REVDEP 8
.Os
.Sh NAME
.Nm revdep
.Nd find packages with broken shared library dependencies
.Sh SYNOPSIS
.Nm
.Op Fl v
.Op Fl i Ar package , Ns Ar ...
.Op Ar package ...
.Nm
.Op Fl v
.Op Fl i Ar package , Ns Ar ...
.Fl r
.Ar package ...
.Nm
.Fl h | V
.Sh DESCRIPTION
.Nm
checks installed packages for shared libraries that the dynamic linker
would not find.
Without a
.Ar package ,
every installed package is checked.
.Pp
The files of a package are read from the package database.
Each one that is an x86_64 executable or shared object is inspected:
every library in its
.Dv DT_NEEDED
entries must be found, as described in
.Sx LIBRARY SEARCH ,
and must itself be an x86_64 ELF file.
Other files, and ELF files for other architectures, are skipped.
A package is broken if one of its files needs a library that is not
found, or if it has files in the directory of an older Python or Perl;
see
.Sx STALE LANGUAGE PATHS .
.Pp
With
.Fl r ,
.Nm
reports the reverse: the packages that link against a shared library
of one of the named packages.
Run it after updating a library to see what may need rebuilding.
A shared library is a file named
.Pa name.so
or
.Pa name.so.\& Ns Ar N ... ;
a package depends on it if a
.Dv DT_NEEDED
entry of one of its files is that name.
.Pp
Options must come before the package names.
The options are as follows:
.Bl -tag -width Ds
.It Fl h
Print a usage summary.
.It Fl i Ar package , Ns Ar ...
Ignore the listed packages: they are not checked, and with
.Fl r
not reported.
May be given more than once.
.It Fl r
Reverse mode, as described above.
Needs at least one
.Ar package .
.It Fl V
Print the version.
.It Fl v
More output; may be given up to four times:
.Bl -tag -width "-vvvv"
.It none
The names of the broken packages, or with
.Fl r
of the dependent packages, one per line, for use in scripts.
.It Fl v
A status line for every package.
.It Fl vv
Also the broken files, or with
.Fl r
the files that need a library of the named packages.
.It Fl vvv
Also which library each broken file misses.
.It Fl vvvv
A trace of everything checked.
.El
.El
.Sh LIBRARY SEARCH
A library is looked for the way the musl dynamic linker does:
.Bl -enum
.It
A
.Dv DT_NEEDED
entry containing a
.Ql /
is taken as a path.
.It
The directories in
.Dv DT_RUNPATH ,
or in
.Dv DT_RPATH
if there is no
.Dv DT_RUNPATH .
.Li $ORIGIN
is replaced by the directory of the file being checked and
.Li $LIB
by
.Li lib .
.It
The system path: the directories in
.Pa /etc/ld-musl-x86_64.path ,
separated by
.Ql \&:
or new lines, if that file exists, otherwise
.Pa /lib ,
.Pa /usr/local/lib
and
.Pa /usr/lib .
.It
The directories listed for the package in
.Pa /etc/revdep.d/ ;
see
.Sx FILES .
.El
.Sh STALE LANGUAGE PATHS
Modules built for one Python or Perl version are installed in a
directory named after it, and are not found once another version is
installed.
.Pp
If the package
.Li python3
is installed, a package with a file under
.Pa /usr/lib/python Ns Ar X.Y Ns Pa /
is broken when
.Ar X.Y
is not the major and minor version of that package.
.Pp
If the package
.Li perl
is installed, a package with a file under
.Pa /usr/lib/perl5/site_perl/ Ns Ar version Ns Pa /
is broken when
.Ar version
is not the version of that package.
.Sh FILES
.Bl -tag -width Ds
.It Pa /var/lib/pkg/db
Package database.
.It Pa /etc/revdep.d/ Ns Ar package
Extra library directories for the files of
.Ar package ,
one per line.
Lines starting with
.Ql #
are comments.
.It Pa /etc/ld-musl-x86_64.path
System library path of the musl dynamic linker, if present.
.El
.Sh EXIT STATUS
Without
.Fl r ,
.Nm
exits 0 if no checked package is broken and 1 otherwise.
With
.Fl r ,
finding dependent packages is not an error; it exits 0.
Both exit 1 if a named package is not installed or the package
database cannot be read.
.Sh EXAMPLES
Check every installed package:
.Pp
.Dl # revdep
.Pp
Check two packages, showing the broken files:
.Pp
.Dl # revdep -vv firefox chromium
.Pp
After updating wlroots and wayland, list what links against them:
.Pp
.Dl # revdep -r wlroots wayland
.Pp
Check everything except the kernel and firmware:
.Pp
.Dl # revdep -i linux,linux-firmware
.Pp
To rebuild a broken package, raise
.Va release
in its port and run
.Ic pkg sysup ;
see
.Xr pkg 8 .
.Sh SEE ALSO
.Xr ldd 1 ,
.Xr readelf 1 ,
.Xr addpkg 8 ,
.Xr infopkg 8 ,
.Xr mkpkg 8 ,
.Xr pkg 8
.Sh AUTHORS
.An zorz Aq Mt zorz@gmx.com ,
after the
.Nm
of James Buren for CRUX.
.Sh CAVEATS
musl also looks for a library in the
.Dv DT_RPATH
or
.Dv DT_RUNPATH
of the program or library that loaded the one needing it.
.Nm
checks each file on its own, so a library found only that way is
reported missing.