coinst - Online in the Cloud

PROGRAM:

NAME

Coinst - computes the co-installability kernel of a package repostory

SYNOPSIS

coinst [options]

DESCRIPTION

coinst reads a package repository in debian format or RPM format from standard input, and
computes the co-installability kernel of the repository (see below). The graph of the
kernel is written in dot format to a file, and a diagnostic is written to standard output.
This diagnostic consists by default of:

- the list of equivalence classes of packages

- the list of non-installable packages

- the list of not co-installable pairs of packages

CO-INSTALLABILITY KERNELS

A set of packages is called co-installable with respect to a repository R if it can be
extended to a set of packages from R that satisfies all inter-package relations
(dependencies, conflicts, etc.). In particular, a package p is installable if the set {p}
consisting of p only is co-installable.

This tool reduces a repository R to a much smaller one, its so-called co-installability
kernel R', that behaves exactly the same as far as co-installability of package is
concerned: Any set of packages P is co-installable with respect to P iff it co-installable
with respect to R'. This is achieved by

- dropping all relations that are not relevant for this purpose. For instance,
dependencies that do not lead directly or indirectly to any conflicts are dropped.

- identifying all packages that behave the same. For instance, packages that are not in
conflict with any other package (even not through dependency chains) behave the same
since they are co-installable together with any other co-installable set of packages,
and packages that are not installable at all behave the same since they may never be
part of any co-installable set of packages.

A more precise explanation can be found in the original research article underlying this
tool.

The interest of computing the kernel is that it is typically orders of magnitude smaller
than the original repository.

OPTIONS

Options controlling the input
-deb expect input in the format of a debian Packages file (default).

-rpm expect input in the format of an RPM hdlist.cz file.

-ignore package
ignore the package named package.

Options controlling the graph output
-o file
write the graph to file instead of graph.dot

-all include all packages in the coinstallability graph

-root p
draw only the relevant portion of the graph around package p.

Options controlling the diagnostic output
-explain
explain the list of non-installable pairs of packages.

-stats show statistics regarding the input and output repositories

Miscellaneous options
-help, --help
show command synopsis

EXAMPLE

Reduce a current debian Packages file to its kernel:

coinst -all -o raw.dot < sid_main_binary-amd64_Packages

Layout the graph:

dot raw.dot -o layout.dot:

View the graph with dotty, or the viewer from the coinst_viewer package:

dotty layout.dot
coinst_viewer layout.dot

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