support home being ldmx sw

[tomeichlersmith]

This resolves #137

A premium is placed on not affecting the current trunk-based workflow of ldmx-sw.

Checks

Changing the environment scripting mainly affects runtime behavior of finding executables and linking them to their libraries. Finding the ldmx-sw executables is tested by running simple simulation through fire., finding the ldmx-sw python config package is tested by running ctest, and finding GENIE-specific libs is tested by running a GENIE simulation. GENIE called out specifically because I am dropping LD_LIBRARY_PATH in favor of ldconfig.

• configure, build, simple sim run of trunk and previous versions (done by CI)
• check that GENIE executables are findable (denv genie-config showed its help message)
• run ctest on trunk for ldmx-sw CI (just test works)
• run GENIE validation sample on trunk for ldmx-sw CI (see below)
• configure, build, simple sim run of 1472-move-denv-into-ldmx-sw for future
• run ctest on 1472-move-denv-into-ldmx-sw
• run GENIE validation sample on 1472-move-denv-into-ldmx-sw

run GENIE

just setenv LDMX_NUM_EVENTS=10
cd .github/validation_samples/target_genie
. init.sh
denv fire config.py

[tomeichlersmith]

Just notes for future me to make sure I covered my bases.

"current trunk" is without changes form 1472-move-denv-into-ldmx-sw while "future" trunk includes them.
Imagining world where the latest dev image includes these changes.

• Current Setups: .profile defines LDMX_BASE=${HOME} and ${HOME} is ldmx-sw parent directory (where .denv is located)
  • on current trunk, switching to a new image without re-init will work because LDMX_BASE is defined correctly so that LDMX_SW_INSTALL is the right path
  • on current trunk, re-init will silently not do anything due to --no-over provided to denv
  • on future trunk, init fails until ldmx-sw/../.denv is deleted, normal operations work because LDMX_BASE is defined properly
• New Setups on current trunk: .profile does not define LDMX_BASE and ${HOME} is ldmx-sw parent
  • init works because ldmx-env-init.sh sees ~/ldmx-sw and sets LDMX_SW_INSTALL accordingly
• New Setups on future trunk: .profile does not define LDMX_BASE and ${HOME} is ldmx-sw
  • init works because ldmx-env-init.sh sees ~/CMakeLists.txt and sets LDMX_SW_INSTALL accordingly