Policy

1. Package Versions

1.1 Definition

<non-native package version> ::= <upstream version> "-" <debian revision>;

<native package version> ::= <upstream version>;

<debian revision> ::= "reading package version from right to left, anything until and not including the first dash (-)";
<upstream version> ::= "reading package version from left to right, anything until and not including the last dash (-)";

Examples

1.2.3: upstream version 1.2.3
1.2.3-4: upstream version 1.2.3, debian revision 4
1.2.3-4+deb13u1: upstream version 1.2.3, debian revision 4+deb13u1
1.2.3-5~bpo13+1: upstream version 1.2.3, debian revision 4~bpo13+1
1.2.3-4-5: upstream version 1.2.3-4, debian revision 5
2025-06-01-1: upstream version 2025-06-01, debian revision 1

1.2 Version Suffix

Upload	Format	Debian Version	Fast Forward Version
Distribution	non-native	1.2.3-4	1.2.3-4ffwd13u1
Distribution	native	1.2.3	1.2.3ffwd13u1
Security/SRM (patch)	non-native	1.2.3-4+deb13u1	1.2.3-4+deb13u1ffwd13u1
Security/SRM (patch)	native	1.2.3+deb13u1	1.2.3+deb13u1ffwd13u1
Security/SRM (backport)	non-native	1.2.3-4~deb13u1	1.2.3-4~deb13u1ffwd13u1
Security/SRM (backport)	native	1.2.3~deb13u1	1.2.3~deb13u1ffwd13u1
Backports	non-native	1.2.3-4	1.2.3-4~ffwd13+u1
Backports	native	1.2.3	1.2.3ffwd13+u1

Upload	Format	Debian Version	Fast Forward Version
binNMU	non-native	1.2.3-4+b1	1.2.3-4+b1ffwd13u1
binNMU	native	1.2.3+b1	1.2.3+b1ffwd13u1
NMU	non-native	1.2.3-4.1	1.2.3-4.1ffwd13u1
NMU	native	1.2.3+nmu1	1.2.3+nmu1ffwd13u1

1.3 Upgrade Paths

dpkg-compare-versions.sh

1.3.1 Debian (without format change)

Path	oldstable	Security/SRM (patch)	Security/SRM (backport)	Backports	stable
non-native (new revision)	1.2.3-4	→ 1.2.3-4+deb13u1	→ 1.2.3-5~deb13u1	→ 1.2.3-5~bpo13+1	→ 1.2.3-5
non-native (new upstream)	1.2.3-4	→ 1.2.3-4+deb13u1	→ 1.2.4-1~deb13u1	→ 1.2.4-1~bpo13+1	→ 1.2.4-1
native (new upstream)	1.2.3	→ 1.2.3+deb13u1	→ 1.2.4~deb13u1	→ 1.2.4~bpo13+1	→ 1.2.4

1.3.2 Debian (with format change)

Path	oldstable	Security/SRM (patch)	Security/SRM (backport)	Backports	stable
native → non-native (new upstream)	1.2.3	→ 1.2.3+deb13u1	→ 1.2.4-1~deb13u1	→ 1.2.4-1~bpo13+1	→ 1.2.4-1
non-native → native (new upstream)	1.2.3-4	→ 1.2.3-4+deb13u1	→ 1.2.4~deb13u1	→ 1.2.4~bpo13+1	→ 1.2.4

1.3.3 Fast Forward (without format change)

Path	oldstable	oldstable +ffwd	Security/SRM (patch)	Security/SRM (patch)+ffwd	Security/SRM (backport)	Security/SRM (backport)+ffwd	Backports ffwd	stable
non-native → non-native (new revision)	1.2.3-4	→ 1.2.3-4ffwd13u1	→ 1.2.3-4+deb13u1	→ 1.2.3-4+deb13u1ffwd13u1	→ 1.2.3-5~deb13u1	→ 1.2.3-5~deb13u1ffwd13u1	→ 1.2.3-5~ffwd13+u1	→ 1.2.3-5
non-native → non-native (new upstream)	1.2.3-4	→ 1.2.3-4ffwd13u1	→ 1.2.3-4+deb13u1	→ 1.2.3-4+deb13u1ffwd13u1	→ 1.2.4-1~deb13u1	→ 1.2.4-1~deb13u1ffwd13u1	→ 1.2.4-1~ffwd13+u1	→ 1.2.4-1
native → native (new upstream)	1.2.3	→ 1.2.3ffwd13u1	→ 1.2.3+deb13u1	→ 1.2.3+deb13u1ffwd13u1	→ 1.2.4~deb13u1	→ 1.2.4~deb13u1ffwd13u1	→ 1.2.4~ffwd13+u1	→ 1.2.4

1.3.4 Fast Forward (with format change)

Path	oldstable	oldstable +ffwd	Security/SRM (patch)	Security/SRM (patch)+ffwd	Security/SRM (backport)	Security/SRM (backport)+ffwd	Backports ffwd	stable
native → non-native (new upstream)	1.2.3	→ 1.2.3ffwd13u1	→ 1.2.3+deb13u1	→ 1.2.3+deb13u1ffwd13u1	→ 1.2.4-1~deb13u1	→ 1.2.4-1~deb13u1ffwd13u1	→ 1.2.4-1~ffwd13+u1	→ 1.2.4-1
non-native → native (new upstream)	1.2.3-4	→ 1.2.3-4ffwd13u1	→ 1.2.3-4+deb13u1	→ 1.2.3-4+deb13u1ffwd13u1	→ 1.2.4~deb13u1	→ 1.2.4~deb13u1ffwd13u1	→ 1.2.4~ffwd13+u1	→ 1.2.4

1.3.5 Fast Forward (with format conversion)

Path	oldstable	oldstable +ffwd	Security/SRM (patch)	Security/SRM (patch)+ffwd	Security/SRM (backport)	Security/SRM (backport)+ffwd	Backports ffwd	stable
native → non-native (new upstream)	1.2.3	→ 1.2.3-0ffwd13u1	→ 1.2.3+deb13u1	→ 1.2.3+deb13u1-0ffwd13u1	→ 1.2.4~deb13u1	→ 1.2.4~deb13u1-0ffwd13u1	→ 1.2.4-0.0~ffwd13+u1	→ 1.2.4
native → non-native (no new version)	1.2.3	→ 1.2.3-0ffwd13u1	—	—	—	—	→ 1.2.3-0.0~ffwd13+u1	→ 1.2.3+b1

1.4 Version Tracking

1.4.1 Tracking Colors

Version tracking by comparing source and all their binary packages on all architectures, after removing vendor suffix:

all upstream versions are equal and all debian revisions are equal → green
all upstream versions are equal and one or more debian revision is lower → orange
one or more upstream version is lower → red
all upstream versions are equal and one or more debian revision is higher → purple
one or more upstream version is higher → purple
source package is in derivative, but not in debian → blue

1.4.2 Version Comparison

architectures:
  all
  amd64
  arm64

suffixes:
  ffwd[0-9]u[0-9]
  ~ffwd[0-9]+u[0-9]
  0ffwd[0-9]u[0-9]
  0~ffwd[0-9]u+[0-9]
  0.0~ffwd[0-9]u+[0-9]
  0ffwd[0-9]+u[0-9]

for derivative_distribution in derivative_distributions:
  for each derivative_source_package in derivate_distribution:
    if derivative_source_package not in parent_source_packages:
      → blue .

    if derivative_source_package_upstream_version > parent_source_package_upstream_version:
      → purple .

    if derivative_source_package_upstream_version < parent_source_package_upstream_version:
      → red .

    if derivative_source_package_upstream_version = parent_source_package_upstream_version:
      if derivative_source_package_debian_revision_without_suffix > parent_source_package_debian_revision:
        → purple .

      if derivative_source_package_debian_revision_without_suffix < parent_source_package_debian_revision:
        → orange .

      if derivative_source_package_debian_revision_without_suffix = parent_source_package_debian_revision:
        for each derivative_binary_package in derivative_source_package:
          if derivative_binary_package in parent_binary_packages:
            for each architecture in architectures:
              get highest_version

            if highest_version is empty:
              → green .

        for each derivative_binary_package in derivative_binary_packages:
          for each architecture in architectures:
            if derivative_binary_package_debian_revision_without_suffix > highest_version:
              → purple on this architecture for this derivative_binary_package

            if derivative_binary_package_debian_revision_without_suffix < highest_version:
              → red on this architecture for this derivative_binary_package

        → green .