due to the bug finder doesn't list any of flux now - since 0.34.07 version. Or i don't know something... How does it work now?
btw, i'm really newb player - haven't beaten any megabeast, haven't got any siedge or real army.
It does show flux in linux, but you have to switch biomes for it to display. Specifically, when you select multiple for shallow metals, multiple for deep metals, flux yes, aquifer no, it will find sites of your embark size with all those features. Under linux, it seems to (at least, some of the time) only shows the metal biome first, you have to press F2 (F3, F4) for it to display the flux/other biome.
I just downloaded a fresh copy of 34.07 for linux, gen'd a custom world, used the finder to find a site with multiple deep & shallow metals, flux, and no aquifer.
Here's the worldgen
Created in DF v0.34.07.
[WORLD_GEN]
[TITLE:FLUX_TEST1]
[SEED:N7vhxT4mk8M1JYTmKAOb]
[HISTORY_SEED:OBZ82wi34TQDO9g9rYAP]
[NAME_SEED:WKCdeTFoTVFdS1ZKp3Yf]
[CREATURE_SEED:nme1lCPQWNbsXbozur0B]
[DIM:65:65]
[EMBARK_POINTS:2500]
[END_YEAR:250]
[BEAST_END_YEAR:250:99]
[REVEAL_ALL_HISTORY:0]
[CULL_HISTORICAL_FIGURES:1]
[ELEVATION:100:400:101:101]
[RAINFALL:10:32:101:101]
[TEMPERATURE:90:90:0:0]
[DRAINAGE:10:49:101:101]
[VOLCANISM:0:0:0:0]
[SAVAGERY:0:0:0:0]
[ELEVATION_FREQUENCY:1:1:1:1:1:1]
[RAIN_FREQUENCY:1:1:1:1:1:1]
[DRAINAGE_FREQUENCY:1:1:1:1:1:1]
[TEMPERATURE_FREQUENCY:1:1:1:1:1:1]
[SAVAGERY_FREQUENCY:1:1:1:1:1:1]
[VOLCANISM_FREQUENCY:1:1:1:1:1:1]
[MINERAL_SCARCITY:500]
[MEGABEAST_CAP:0]
[SEMIMEGABEAST_CAP:0]
[TITAN_NUMBER:0]
[TITAN_ATTACK_TRIGGER:80:0:0]
[DEMON_NUMBER:0]
[NIGHT_TROLL_NUMBER:0]
[BOGEYMAN_NUMBER:0]
[VAMPIRE_NUMBER:0]
[WEREBEAST_NUMBER:0]
[SECRET_NUMBER:0]
[REGIONAL_INTERACTION_NUMBER:0]
[DISTURBANCE_INTERACTION_NUMBER:0]
[EVIL_CLOUD_NUMBER:0]
[EVIL_RAIN_NUMBER:0]
[GOOD_SQ_COUNTS:0:0:0]
[EVIL_SQ_COUNTS:0:0:0]
[PEAK_NUMBER_MIN:0]
[PARTIAL_OCEAN_EDGE_MIN:0]
[COMPLETE_OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:0]
[REGION_COUNTS:SWAMP:0:0:0]
[REGION_COUNTS:DESERT:0:0:0]
[REGION_COUNTS:FOREST:0:0:0]
[REGION_COUNTS:MOUNTAINS:0:0:0]
[REGION_COUNTS:OCEAN:0:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:0:0:0]
[REGION_COUNTS:HILLS:0:0:0]
[EROSION_CYCLE_COUNT:0]
[RIVER_MINS:0:0]
[PERIODICALLY_ERODE_EXTREMES:0]
[OROGRAPHIC_PRECIPITATION:0]
[SUBREGION_MAX:2750]
[CAVERN_LAYER_COUNT:1]
[CAVERN_LAYER_OPENNESS_MIN:10]
[CAVERN_LAYER_OPENNESS_MAX:15]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:0]
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:0]
[CAVERN_LAYER_WATER_MIN:10]
[CAVERN_LAYER_WATER_MAX:15]
[HAVE_BOTTOM_LAYER_1:1]
[HAVE_BOTTOM_LAYER_2:1]
[LEVELS_ABOVE_GROUND:1]
[LEVELS_ABOVE_LAYER_1:40]
[LEVELS_ABOVE_LAYER_2:16]
[LEVELS_ABOVE_LAYER_3:2]
[LEVELS_ABOVE_LAYER_4:2]
[LEVELS_ABOVE_LAYER_5:3]
[LEVELS_AT_BOTTOM:2]
[CAVE_MIN_SIZE:1]
[CAVE_MAX_SIZE:1]
[MOUNTAIN_CAVE_MIN:0]
[NON_MOUNTAIN_CAVE_MIN:0]
[ALL_CAVES_VISIBLE:1]
[SHOW_EMBARK_TUNNEL:2]
[TOTAL_CIV_NUMBER:5]
[TOTAL_CIV_POPULATION:5000]
[SITE_CAP:10]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:0:0:0]
[RAIN_RANGES:0:0:0]
[DRAINAGE_RANGES:0:0:0]
[SAVAGERY_RANGES:0:0:0]
[VOLCANISM_RANGES:0:0:0]
And here's the embark location:
As you'll note, there are two Biomes there, press F2 and it will show the flux biome.
For this world, you'll have two civs to interact with, and they'll likely bring cave dragons and trolls, at least, with them during sieges.
Civilized World Population
1480 Dwarves
861 Humans
22083 Goblins
Total: 24424
Embark level is 144. At layers 141 through 136, (just below the soil layers) there is limestone and limonite. Steel for you!