$  make clean   
[CLEAN PNML]
[CLEAN NML]
[CLEAN LNG]
[CLEAN GRF]
[CLEAN DOC]
[CLEAN BUNDLE]
[CLEAN BUNDLE SRC]

$  time make -j1
[GENERATE PNML]
python scripts/preprocess.py 'FIRS Industry Replacement Set 2015-01-24 (5502:abc336a88976)' '4053' '' ''
[PYTHON] python preprocessing
[PYTHON] render pnml
Linking
16.43s
[PYTHON] render docs
[PARSE BASE LANG & EXTRA STRINGS] utils.py
1.33s
[CPP] generated/firs.nml
[LNG] custom_tags.txt
[NML] firs.grf
 nmlc warning: "lang/serbian.lng", line 123: String commands don't match with master file "english.lng"
 nmlc warning: "lang/serbian.lng", line 129: String commands don't match with master file "english.lng"
 nmlc warning: "lang/esperanto.lng", line 122: String commands don't match with master file "english.lng"
 nmlc warning: "lang/esperanto.lng", line 128: String commands don't match with master file "english.lng"
 nmlc warning: "lang/welsh.lng", line 122: String commands don't match with master file "english.lng"
 nmlc warning: "lang/welsh.lng", line 128: String commands don't match with master file "english.lng"
 nmlc warning: "lang/slovak.lng", line 133: String commands don't match with master file "english.lng"
 nmlc warning: "lang/slovak.lng", line 140: String commands don't match with master file "english.lng"
 nmlc warning: "lang/czech.lng", line 99: String commands don't match with master file "english.lng"
 nmlc warning: "lang/czech.lng", line 104: String commands don't match with master file "english.lng"
 nmlc warning: "lang/romanian.lng", line 125: String commands don't match with master file "english.lng"
 nmlc warning: "lang/romanian.lng", line 132: String commands don't match with master file "english.lng"
 nmlc info: 1823 sprites, 1162 cached, 1 orphaned, 350 duplicates, 311 newly encoded (python)
 nmlc info: Industry Tile items: 132/256
 nmlc info: Industry items: 64/64
 nmlc info: Cargo items: 31/32
 nmlc info: Concurrent Action10 labels: 2/240 ("generated/pnml/checks.pnml", line 72)
 nmlc info: Concurrent spritesets: 24/255 ("generated/pnml/bulk_terminal.pnml", line 1417)
 nmlc info: Concurrent spritegroups: 156/256 ("generated/pnml/orchard_piggery.pnml", line 55882)
 nmlc info: Concurrent Action2 registers: 99/127 ("generated/pnml/machine_shop.pnml", line 4638)
 nmlc info: Concurrent ActionD registers: 42/64 ("generated/pnml/forest.pnml", line 170)
 nmlc info: GRF parameter registers: 6/64
 nmlc info: Cargo translation table: 40/254
 nmlc info: D0xx strings: 74/1024
 nmlc info: DCxx strings: 144/256
 nmlc warning: "generated/pnml/aluminium_plant.pnml", line 599: "src/graphics/industries/aluminium_plant_3.png" at [x: 430, y: 10]: 4 of 3584 pixels (0%) are animated                                                                                                                          
 nmlc warning: "generated/pnml/aluminium_plant.pnml", line 606: "src/graphics/industries/aluminium_plant_3_snow.png" at [x: 430, y: 10]: 4 of 3584 pixels (0%) are animated

# .....  lots of warning omitted
[BUNDLE] firs
[BUNDLE TAR] firs.tar
make -j1  164.40s user 4.30s system 130% cpu 2:09.07 total

$  time make -j1
[CPP] generated/firs.nml
[LNG] custom_tags.txt
[NML] firs.grf

# Lines omitted

[BUNDLE] firs
[BUNDLE TAR] firs.tar
make -j1  105.55s user 3.03s system 99% cpu 1:48.66 total