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Last modified: 3 December 2014


Bugs: Building CIAO from Source

Table of Contents




pkg-config must be version 0.18 or newer

To find out the version on your system:

pkg-config --version

If it is older then 0.18 or is not installed, you can the pkg-config included with the CIAO OTS.

setenv PATH <location of ciao>/ciao-4.4/ots/bin:$PATH

This must be done before running configure.

Download the binary tarfiles to use the precompiled OTS

If you are building from source but wish to use the compiled OTS packaged with CIAO (e.g. the CIAO copy of Python), it is necessary to download both the source and binary files.

Incompatible GCC compiler on Mac 10.7 (Lion)

Apple has upgraded the gcc compiler in the latest version of the developer toolkit from 4.2.1 to 4.4.1. This update impacts the source build of CIAO on Lion. Please contact the CXC Helpdesk if you require assistance in building CIAO with the new compiler.

Building 32 bit CIAO on a 64 bit machine: if chips, transforms and crates fail to build

When performing a 32 bit build on a 64 bit machine, the chips, transforms and crates directories may fail to build. After running the configure command, the file src/include/Makefile.cxc needs to be updated to add the following two macro definitions which are necessary to compile the transforms, crates, and chips python modules:

CCFLAGS = -m32
FFLAGS = -m32



The $ASCDS_INSTALL/INSTALL_SOURCE instructions that are included in the CIAO 4.7 distribution are incorrect. The order of some of the commands has changed. Users wanting to do a source build should follow the instructions in this updated copy of INSTALL_SOURCE

Source builds with CIAO using OSX llvm

Newer versions XCode (> 4.2) have switched to using the 'llvm' compiler instead GNU's gcc. There are several incompatibilities in llvm that cause building CIAO to fail.

The llvm compilers have a GNU back compatiblitity mode that is enabled by set the compilers expliciity before running configure (or python

bash> export CC=/usr/bin/gcc
bash> export CXX=/usr/bin/g++ 

tcsh% setenv CC /usr/bin/gcc
tcsh% setenv CXX /usr/bin/g++

make or make install?

After running ./configure with the correct flags to setup for a source build users may, depending on the packages they downloaded, see a message about running make or make install. Users must run make install.

Building sherpa using pre-compiled XSPEC library requires same version of gfortran

Users building sherpa from source with the CIAO pre-compiled binary OTS packages (recommended) may run into a problem that the version of FORTRAN used to build XSpec must be the same as is used to build sherpa.

Specifically this means that sherpa must be built to link against Most new gfortran compilers will want to link against

Users may need to recompile the XSpec library according to the instructions in the INSTALL_SOURCE file with the same compiler or may consider installing an older version of gfortran to compile sherpa.

Last modified: 3 December 2014
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