dpkg-architecture - set and determine the architecture for package building .
dpkg-architecture [options] [commands]
dpkg-architecture does provide a facility to determine and set the build and host architecture for package building.
The build architecture is always determined by an external call to dpkg(1), and can not be set at the command line.
You can specify the host architecture by providing one or both of the options -a and -t. The default is determined by an external call to gcc(1), or the same as the build architecture if \s-1CC\s0 or gcc are both not available. One out of -a and -t is sufficient, the value of the other will be set to a usable default. Indeed, it is often better to only specify one, because dpkg-architecture will warn you if your choice does not match the default. .
Print the environment variables, one each line, in the format VARIABLE=value. This is the default action.
I -e debian-architecture
Check for equality of architecture. By default debian-architecture is compared against the current Debian architecture, being the host. This action will not expand the architecture wildcards. Command finishes with an exit status of 0 if matched, 1 if not matched.
I -i architecture-wildcard
Check for identity of architecture by expanding architecture-wildcard as an architecture wildcard and comparing against the current Debian architecture. Command finishes with an exit status of 0 if matched, 1 if not matched.
I -q variable-name
Print the value of a single variable.
Print an export command. This can be used to set the environment variables using eval.
Print a similar command to -s but to unset all variables.
I -c command
Execute a command in an environment which has all variables set to the determined value.
Print a list of valid architecture names.
Show the usage message and exit.
Show the version and exit. .
I -a debian-architecture
Set the Debian architecture.
I -t gnu-system-type
Set the GNU system type.
Values set by existing environment variables with the same name as used by the scripts are honored (i.e. used by dpkg-architecture), except if this force flag is present. This allows the user to override a value even when the call to dpkg-architecture is buried in some other script (for example dpkg-buildpackage(1)). .
"build The machine the package is built on.
"host The machine the package is built for.
"Debian The Debian architecture string, which specifies the binary tree in the \s-1FTP\s0 archive. Examples: i386, sparc, hurd-i386.
"architecture An architecture wildcard is a special architecture string that will match any real architecture being part of it. The general form is <kernel>-<cpu>. Examples: linux-any, any-i386, hurd-any.
"\s-1GNU\s0 An architecture specification string consisting of two parts separated by a dash: cpu and system. Examples: i386-linux-gnu, sparc-linux-gnu, i386-gnu, x86_64-netbsd. .
The following variables are set by dpkg-architecture:
"\s-1DEB_BUILD_ARCH\s0" The Debian architecture of the build machine.
"\s-1DEB_BUILD_ARCH_OS\s0" The Debian system name of the build machine.
"\s-1DEB_BUILD_ARCH_CPU\s0" The Debian cpu name of the build machine.
"\s-1DEB_BUILD_GNU_TYPE\s0" The \s-1GNU\s0 system type of the build machine.
"\s-1DEB_BUILD_GNU_CPU\s0" The \s-1CPU\s0 part of \s-1DEB_BUILD_GNU_TYPE\s0
"\s-1DEB_BUILD_GNU_SYSTEM\s0" The System part of \s-1DEB_BUILD_GNU_TYPE\s0.
"\s-1DEB_HOST_ARCH\s0" The Debian architecture of the host machine.
"\s-1DEB_HOST_ARCH_OS\s0" The Debian system name of the host machine.
"\s-1DEB_HOST_ARCH_CPU\s0" The Debian cpu name of the host machine.
"\s-1DEB_HOST_GNU_TYPE\s0" The \s-1GNU\s0 system type of the host machine.
"\s-1DEB_HOST_GNU_CPU\s0" The \s-1CPU\s0 part of \s-1DEB_HOST_GNU_TYPE\s0.
"\s-1DEB_HOST_GNU_SYSTEM\s0" The System part of \s-1DEB_HOST_GNU_TYPE\s0. .
The environment variables set by dpkg-architecture are passed to debian/rules as make variables (see make documentation). However, you should not rely on them, as this breaks manual invocation of the script. Instead, you should always initialize them using dpkg-architecture with the -q option. Here are some examples, which also show how you can improve the cross compilation support in your package:
ARCH=\`dpkg --print-architecture\` configure $(\s-1ARCH\s0)-linux
please use the following:
\s-1DEB_BUILD_GNU_TYPE\s0 := $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE) \s-1DEB_HOST_GNU_TYPE\s0 := $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE) configure --build=$(\s-1DEB_BUILD_GNU_TYPE\s0) --host=$(\s-1DEB_HOST_GNU_TYPE\s0)
ARCH=\`dpkg --print-architecture\` ifeq ($(\s-1ARCH\s0),alpha) ... endif
\s-1DEB_HOST_ARCH\s0 := $(shell dpkg-architecture -qDEB_HOST_ARCH) ifeq ($(\s-1DEB_HOST_ARCH\s0),alpha) ... endif
or if you only need to check the CPU or OS type, use the DEB_HOST_ARCH_CPU or DEB_HOST_ARCH_OS variables.
In general, calling dpkg in the rules file to get architecture information is deprecated (unless you want to provide backward compatibility, see below). Especially the --print-architecture option is unreliable since we have Debian architectures which don't equal a processor name. .
The DEB_HOST_ARCH_CPU and DEB_HOST_ARCH_OS variables were only introduced in relatively recent versions of dpkg-architecture (since dpkg 1.13.2), before this debian/rules files tended to check the values of the DEB_HOST_GNU_CPU or DEB_HOST_GNU_TYPE variables which have been subject to change.
Where debian/rules files check these variables to decide how or what to compile, this should be updated to use the new variables and values. You may wish to retain backwards compatibility with older version of dpkg-dev by using the following code:
DEB_HOST_ARCH_CPU := $(shell dpkg-architecture -qDEB_HOST_ARCH_CPU 2>/dev/null) DEB_HOST_ARCH_OS := $(shell dpkg-architecture -qDEB_HOST_ARCH_OS 2>/dev/null) # Take account of old dpkg-architecture output. ifeq ($(DEB_HOST_ARCH_CPU),) DEB_HOST_ARCH_CPU := $(shell dpkg-architecture -qDEB_HOST_GNU_CPU) ifeq ($(DEB_HOST_ARCH_CPU),x86_64) DEB_HOST_ARCH_CPU := amd64 endif endif ifeq ($(DEB_HOST_ARCH_OS),) DEB_HOST_ARCH_OS := $(subst -gnu,,$(shell dpkg-architecture -qDEB_HOST_GNU_SYSTEM)) ifeq ($(DEB_HOST_ARCH_OS),gnu) DEB_HOST_ARCH_OS := hurd endif endif
And similarly for DEB_BUILD_ARCH_CPU and DEB_BUILD_ARCH_OS.
If you still wish to support versions of dpkg-dev that did not include dpkg-architecture, the following does the job:
\s-1DEB_BUILD_ARCH\s0 := $(shell dpkg --print-architecture) \s-1DEB_BUILD_GNU_CPU\s0 := $(patsubst hurd-%,%,$(\s-1DEB_BUILD_ARCH\s0)) ifeq ($(filter-out hurd-%,$(\s-1DEB_BUILD_ARCH\s0)),) \s-1DEB_BUILD_GNU_SYSTEM\s0 := gnu else \s-1DEB_BUILD_GNU_SYSTEM\s0 := linux-gnu endif DEB_BUILD_GNU_TYPE=$(\s-1DEB_BUILD_GNU_CPU\s0)-$(\s-1DEB_BUILD_GNU_SYSTEM\s0) \s-1DEB_HOST_ARCH\s0 := $(\s-1DEB_BUILD_ARCH\s0) \s-1DEB_HOST_GNU_CPU\s0 := $(\s-1DEB_BUILD_GNU_CPU\s0) \s-1DEB_HOST_GNU_SYSTEM\s0 := $(\s-1DEB_BUILD_GNU_SYSTEM\s0) \s-1DEB_HOST_GNU_TYPE\s0 := $(\s-1DEB_BUILD_GNU_TYPE\s0)
Put a subset of these lines at the top of your debian/rules file; these default values will be overwritten if dpkg-architecture is used.
You don't need the full set. Choose a consistent set which contains the values you use in the rules file. For example, if you only need the host Debian architecture, `DEB_HOST_ARCH=\`dpkg --print-architecture\`' is sufficient (this is indeed the Debian architecture of the build machine, but remember that we are only trying to be backward compatible with native compilation).
The -e and -i options were only introduced in relatively recent versions of dpkg-architecture (since dpkg 1.13.13). .
dpkg-buildpackage accepts the -a option and passes it to dpkg-architecture. Other examples:
CC=i386-gnu-gcc dpkg-architecture CW-c debian/rules build
eval \`dpkg-architecture CW-u\`
Check if an architecture is equal to the current architecture or a given one:
dpkg-architecture -amips -elinux-mips
Check if the current architecture or an architecture provided with -a are Linux systems:
dpkg-architecture -ai386 -ilinux-any .
dpkg-architecture and this man page were initially written by Marcus Brinkmann <firstname.lastname@example.org>.