dpkg-shlibdeps


SYNOPSIS
       dpkg-shlibdeps [options] executable|-eexecutable [options]

DESCRIPTION
       dpkg-shlibdeps  calculates  shared library dependencies for executables
       named in its arguments. The dependencies are added to the  substitution
       variables  file  debian/substvars  as variable names shlibs:dependency-
       field where dependencyfield is a dependency field name. Any other vari-
       ables starting shlibs: are removed from the file.

       dpkg-shlibdeps  has  two  possible  sources  of information to generate
       dependency information. Either symbols files or shlibs files. For  each
       binary that dpkg-shlibdeps analyzes, it finds out the list of libraries
       that it's linked with.  Then, for each library, it looks up either  the
       symbols  file,  or  the  shlibs file (if the former doesn't exist or if
       debian/shlibs.local contains the relevant dependency). Both  files  are
       supposed  to  be  provided  by  the  library package and should thus be
       available        as        /var/lib/dpkg/info/package.symbols        or
       /var/lib/dpkg/info/package.shlibs.  The  package  name is identified in
       two steps: find the library file on the system  (looking  in  the  same
       directories  that  ld.so  would  use), then use dpkg -S library-file to
       lookup the package providing the library.

   Symbols files
       Symbols files contain finer-grained dependency information by providing
       the  minimum  dependency  for each symbol that the library exports. The
       script tries to find a symbols file associated to a library package  in
       the following places (first match is used):

       debian/*/DEBIAN/symbols
              Shared  library  information  generated  by  the  current  build
              process that also invoked dpkg-shlibdeps.  They are generated by
              dpkg-gensymbols(1).   They are only used if the library is found
              in a package's build tree. The symbols file in that  build  tree
              takes precedence over symbols files from other binary packages.

       /etc/dpkg/symbols/package.symbols.arch

       /etc/dpkg/symbols/package.symbols
              Per-system  overriding  shared  library  dependency information.
              arch is the architecture of  the  current  system  (obtained  by
              dpkg-architecture -qDEB_HOST_ARCH).

       admindir/info/package.symbols
              Package-provided  shared library dependency information.  Unless
              overridden, admindir is /var/lib/dpkg.

       While scanning the symbols used by all binaries, dpkg-shlibdeps  remem-
       bers  the (biggest) minimal version needed for each library. At the end
       of the process, it is able to write  out  the  minimal  dependency  for
       every  library used (provided that the information of the symbols files
       are accurate).

       first file providing information for the library of interest is used:

       debian/shlibs.local
              Package-local overriding shared library dependency information.

       /etc/dpkg/shlibs.override
              Per-system overriding shared library dependency information.

       debian/*/DEBIAN/shlibs
              Shared  library  information  generated  by  the  current  build
              process that also invoked dpkg-shlibdeps.  They are only used if
              the  library is found in a package's build tree. The shlibs file
              in that build tree takes precedence over shlibs files from other
              binary packages.

       admindir/info/package.shlibs
              Package-provided  shared library dependency information.  Unless
              overridden, admindir is /var/lib/dpkg.

       /etc/dpkg/shlibs.default
              Per-system default shared library dependency information.

       The extracted dependencies are then directly used (except if  they  are
       filtered  out  because  they  have  been identified as duplicate, or as
       weaker than another dependency).

OPTIONS
       dpkg-shlibdeps interprets non-option  arguments  as  executable  names,
       just as if they'd been supplied as -eexecutable.

       -eexecutable
              Include   dependencies  appropriate  for  the  shared  libraries
              required by executable.

       -ddependencyfield
              Add dependencies to be added  to  the  control  file  dependency
              field  dependencyfield.   (The  dependencies  for this field are
              placed in the variable shlibs:dependencyfield.)

              The -ddependencyfield option takes effect  for  all  executables
              after the option, until the next -ddependencyfield.  The default
              dependencyfield is Depends.

              If the same dependency entry (or set of alternatives) appears in
              more   than   one  of  the  recognised  dependency  field  names
              Pre-Depends, Depends,  Recommends,  Enhances  or  Suggests  then
              dpkg-shlibdeps will automatically remove the dependency from all
              fields except the one representing the most important  dependen-
              cies.

       -pvarnameprefix
              Start  substitution  variables  with  varnameprefix:  instead of
              shlibs:.  Likewise, any existing substitution variables starting
              with  varnameprefix:  (rather than shlibs:) are removed from the

       -Llocalshlibsfile
              Read  overriding  shared  library  dependency  information  from
              localshlibsfile instead of debian/shlibs.local.

       -Tsubstvarsfile
              Write substitution variables in substvarsfile;  the  default  is
              debian/substvars.

       -v     Enable  verbose mode. Numerous messages are displayed to explain
              what dpkg-shlibdeps does.

       -xpackage
              Exclude the package from the  generated  dependencies.  This  is
              useful to avoid self-dependencies for packages which provide ELF
              binaries (executables or library plugins) using a  library  con-
              tained  in  the  same  package. This option can be used multiple
              times to exclude several packages.

       -Spkgbuilddir
              Look into pkgbuilddir first when trying to find a library.  This
              is useful when the source package builds multiple flavors of the
              same library and you want to ensure that you get the  dependency
              from  a  given  binary package. You can use this option multiple
              times: directories will be tried in the same order before direc-
              tories of other binary packages.

       --ignore-missing-info
              Do  not  fail  if  dependency  information  can't be found for a
              shared library.   Usage  of  this  option  is  discouraged,  all
              libraries  should  provide  dependency  information (either with
              shlibs files, or with symbols files) even if they  are  not  yet
              used by other packages.

       --warnings=value
              value  is  a  bit field defining the set of warnings that can be
              emitted by dpkg-shlibdeps.  Bit 0 (value=1) enables the  warning
              "symbol  sym used by binary found in none of the libraries", bit
              1 (value=2) enables the warning "dependency on library could  be
              avoided"  and  bit  2  (value=4)  enables  the  warning  "binary
              shouldn't be linked with library".  The default value is 3:  the
              first  two  warnings are active by default, the last one is not.
              Set value to 7 if you want all warnings to be active.

       --admindir=dir
              Change the location of the dpkg database. The  default  location
              is /var/lib/dpkg.

       -h, --help
              Show the usage message and exit.

       --version
              Show the version and exit.

              process (option -llibrary of the linker).

       binary  contains an unresolvable reference to symbol sym: it's probably
       a plugin
              The indicated symbol has not been found in the libraries  linked
              with the binary. The binary is most likely a plugin and the sym-
              bol is probably provided by the program that loads this  plugin.
              In  theory a plugin doesn't have any SONAME but this binary does
              have one and as such it could not be clearly identified as such.
              However  the  fact  that  the  binary  is stored in a non-public
              directory is a strong indication that's it's not a normal shared
              library.  If  the binary is really a plugin, then disregard this
              warning. But there's always the possibility  that  it's  a  real
              library  and  that  programs linking to it are using an RPATH so
              that the dynamic loader finds it. In that case, the  library  is
              broken and needs to be fixed.

       dependency  on  library could be avoided if binaries were not uselessly
       linked against it (they use none of its symbols).
              None of the binaries that are linked with library use any of the
              symbols provided by the library. By fixing all the binaries, you
              would avoid the dependency associated to  this  library  (unless
              the same dependency is also generated by another library that is
              really used).

       binary shouldn't be linked with library (it uses none of its symbols).
              The binary is linked to a library that it doesn't need. It's not
              a problem but some small performance improvements in binary load
              time can be obtained by not linking this library to this binary.
              This  warning  checks the same information than the previous one
              but does it for each binary instead of doing the check  globally
              on all binaries analyzed.

ERRORS
       dpkg-shlibdeps  will  fail  if it can't find a public library used by a
       binary or if this library  has  no  associated  dependency  information
       (either shlibs file or symbols file). A public library has a SONAME and
       is versioned (libsomething.so.X). A private  library  (like  a  plugin)
       should not have a SONAME and doesn't need to be versioned.

       couldn't  find  library  library-soname  needed by binary (its RPATH is
       'rpath')
              The binary uses a library called library-soname but  dpkg-shlib-
              deps  has  been unable to find the library.  dpkg-shlibdeps cre-
              ates a list of directories to check  as  following:  directories
              listed  in  the  RPATH  of  the  binary,  directories  listed in
              /etc/ld.so.conf, directories listed in the LD_LIBRARY_PATH envi-
              ronment   variable,   and  standard  public  directories  (/lib,
              /usr/lib,  /lib32,  /usr/lib32,  /lib64,  /usr/lib64).  Then  it
              checks  those  directories  in  the  package's build tree of the
              binary being analyzed, in the packages's build  trees  indicated
              with the -S command-line option, in other packages's build trees
              that contains a DEBIAN/shlibs or DEBIAN/symbols file and finally
              in  the  root  directory.  If the library is not found in any of
              dependency  information for that library. To find out the depen-
              dency, it has tried to map the library to a Debian package  with
              the  help  of  dpkg -S library-file.  Then it checked the corre-
              sponding shlibs and symbols files in /var/lib/dpkg/info/, and in
              the various package's build trees (debian/*/DEBIAN/).

              This failure can be caused by a bad or missing shlibs or symbols
              file in the package of the library. It might also happen if  the
              library  is  built  within  the  same  source package and if the
              shlibs files has not yet been created (in which  case  you  must
              fix debian/rules to create the shlibs before calling dpkg-shlib-
              deps). Bad RPATH can also lead to the library being found  under
              a    non-canonical   name   (example:   /usr/lib/gcc/i486-linux-
              gnu/4.2.3/../../../../lib/libssl.so.9.8 instead of /usr/lib/lib-
              ssl.so.0.9.8)  that's not associated to any package, dpkg-shlib-
              deps tries to work around this by trying to fallback on a canon-
              ical name (using realpath(3)) but it might not always work. It's
              always best to clean up the RPATH of the binary to  avoid  prob-
              lems.

              Calling  dpkg-shlibdeps  in  verbose mode (-v) will provide much
              more information about where it tried  to  find  the  dependency
              information.  This  might  be useful if you don't understand why
              it's giving you this error.

SEE ALSO
       deb-shlibs(5), deb-symbols(5), dpkg-gensymbols(1).

AUTHORS
       Copyright (C) 1995-1996 Ian Jackson
       Copyright (C) 2000 Wichert Akkerman
       Copyright (C) 2006 Frank Lichtenheld
       Copyright (C) 2007-2008 Raphael Hertzog

       This is free software; see the GNU General Public Licence version 2  or
       later for copying conditions. There is NO WARRANTY.



Debian Project                    2009-03-08                 dpkg-shlibdeps(1)
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