message: Only run CheckESC.C if we have AliPhysics
  CheckESD.C requires AliPhysics to run, but in CI it isn't always available.
diff: @@ -6,7 +6,10 @@ aliroot -b -q sim.C 2>&1 | tee sim.log
  mv syswatch.log simwatch.log
  aliroot -b -q rec.C 2>&1 | tee rec.log
  mv syswatch.log recwatch.log
  -aliroot -b -q ${ALICE_ROOT}/STEER/macros/CheckESD.C 2>&1 | tee check.log
  +if [ -n "$ALICE_PHYSICS" ]; then
  + # For this macro, we need OADB, which is part of AliPhysics.
  + aliroot -b -q "$ALICE_ROOT/STEER/macros/CheckESD.C" 2>&1 | tee check.log
  +fi
  aliroot -b -q aod.C 2>&1 | tee aod.log
  cd recraw
  