GPRbuild on OpenBSD


This page describes how I could build GPRbuild (the project manager of the GNAT toolchain) from source on OpenBSD 6.6.

The process is documented in the GPRbuild GitHub repository (and in the XML/Ada GitHub repository for the XML/Ada build) but I had a few difficulties due to the specifics of OpenBSD. In particular, the GCC version that comes with the OpenBSD base installation is not the one that must be used to build GPRbuild. A newer one must be used (version 8.3.0) and is not installed as gcc but as egcc. egcc is not recognised automatically by the building tool.

The GPRbuild and XML/Ada versions (commit hashes) I used are:

  • f3d62455b02564a4bbdc1ec04f1da788f22702fe (2019-12-25) for GPRBuild.
  • b50bc2659637695f3a4cf5f0568a537a3e033047 (2019-11-18) for XML/Ada.


GCC and GNAT 8.3.0p4 must be installed. Please read the “My first steps with OpenBSD” page for more details.

GNU make must also be installed:

pkg_add gmake # As root.

Git should be installed as well. It makes cloning the GPRbuild and XML/Ada repositories much easier:

pkg_add git # As root.

Building and installing GPRbuild

Cloning the repositories and creating a bootstrapped GPRbuild

As a “normal” (non root) user, create a working directory and clone the GPRbuild and XML/Ada repositories:

mkdir ~/bootstrapped_gprbuild
cd ~/bootstrapped_gprbuild
git clone
git clone

Then move to the gprbuild directory and edit the edit the script, to remove the -t option on the install commands (four occurrences, near the end of the script). (Because the -t option is not recognized (and not needed) by the OpenBSD install program.)

You can now create the bootsrapped GPRbuild:

./ --with-xmlada=../xmlada --prefix=./bootstrap

Configuring, building and installing XML/Ada

As a normal user, move to the gprbuild directory and create a GPRbuild default configuration file (default.cgpr):

cd ~/bootstrapped_gprbuild/gprbuild
gprconfig --batch --config Ada --config C # Creates the default.cgpr file.

Copy default.cgpr to the xmlada directory:

cp default.cgpr ../xmlada

Move to the xmlada directory and configure the XML/Ada sources:

cd ../xmlada
./configure --prefix=/usr/local

/usr/local is the prefix used for the GNAT installation, as suggested by which gnat or gnatls -v.

Then as root, add the gprbuild directory to the path and build and install XML/Ada:

export PATH=/home/<username>/bootstrapped_gprbuild/gprbuild:"$PATH" # As root.
cd /home/<username>/bootstrapped_gprbuild/xmlada                    # As root.
gmake all install                                                   # As root.

Configuring, building and installing GPRBuild

As a normal user, make sure that the gprbuild directory is in the path (issue a export PATH=~/bootstrapped_gprbuild/gprbuild:"$PATH" command if needed).

Move to the gprbuild directory and configure the GPRbuild sources:

cd ~/bootstrapped_gprbuild/gprbuild
gmake prefix=/usr/local setup

Edit the default.cgpr file: for the Ada binder driver, substitute libexec/gprbuild/gprbind with bootstrap/libexec/gprbuild/gprbind.

Then build GPRbuild:

gmake all

Finally as root, make sure that the gprbuild directory is in the path (issue a export PATH=/home/<username>/bootstrapped_gprbuild/gprbuild:"$PATH" command if needed), move to the gprbuild directory and install GPRbuild:

cd /home/<username>/bootstrapped_gprbuild/gprbuild
gmake install TARGET=$(egcc -dumpmachine)

(The TARGET=$(egcc -dumpmachine) part is needed because by default the Makefile obtains the target from a gcc -dumpmachine command (which invokes /usr/bin/gcc (GCC 4.2.1) and yields “amd64-unknown-openbsd6.6”) whereas we want the output of /usr/local/bin/egcc -dumpmachine (“x86_64-unknown-openbsd6.6”).)

GPRbuild and companion tools should now be installed in /usr/local/bin:

ls -1 /usr/local/bin/gpr*

should give: