View source for Building Offline with cmake

=Introduction=
Use of CMake to build Offline in the DAQ environment.

==Building Offline with CMake==

===Using UPS===

The UPS-based build of Offline is supported in SL7 environments, in two distinct flavors:

====Package-based build====

The Offline CMake uses the ''cetmodules'' package for several CMake convenience functions, and can be built using the standard ''cetmodules'' invocation:

<pre>
source /cvmfs/mu2e.opensciencegrid.org/setupmu2e-art.sh
git clone https://github.com/Mu2e/Offline.git
mkdir build_Offline && cd build_Offline
source ../Offline/ups/setup_for_development -p e28:s126 # -d or -p are supported, see Offline/ups/product_deps for supported qualifier combinations
buildtool # -p to create a UPS-redistributable package, -i to install in a UPS area (-I to specify which)
</pre>

====MRB-based build====

Offline is also compatible with MRB-based development:

<pre>
source /cvmfs/mu2e.opensciencegrid.org/setupmu2e-art.sh
setup mrb
mkdir my_mrb_working_area
export MRB_PROJECT=Mu2e
mrb newDev -v v1_00_00 -q e28:s126:prof # Version here is mostly meaningless, but required to silence certain CMake warnings
cd srcs
mrb gitCheckout https://github.com/Mu2e/Offline.git
mrb uc
mrb z
mrbsetenv
mrb b
</pre>

===Using Spack===

==When to Update CMakeLists.txt==

In general, CMakeLists.txt in affected packages should be updated when:

# Files are added, removed, or renamed
# Library dependencies for a package change (e.g. a #include referring to another package is added or removed)
# Data files are added to a package and should be installed when Offline is built