I was quite confident it has something with the face-facing camera broken in FXP but as a fix was promised for FXP148 I stayed on the patient side.
I thundered 148 this morning and while the camera flash is fixed there, the rest keeps as broken as my English.
Here's the important part of logcat:
I/ActivityManager( 362): START {flg=0x10000 cmp=com.instagram.android/.activity.MediaCaptureActivity u=0} from pid 9175
I/CameraService( 4185): Opening camera 1
W/ServiceManager( 4185): Permission failure: com.sonyericsson.permission.CAMERA_EXTENDED from uid=10057 pid=9175
I/caladbolg( 4185): 380936309 cald_camctrl.c (6713) 9289 P [SVR] 380936248 + Cald_CamCtrl_PowerUp
I/caladbolg( 4185): 381160583 cald_camctrl.c (7484) 9289 P [SVR] 381160522 + Cald_CamCtrl_FSM_Func_PowerUp
I/caladbolg( 4185): 381203338 cald_hal_qct.c (2789) 9289 P [HAL] 381203247 + Cald_Hal_Qct_If_PowerUp
I/caladbolg( 4185): 381208679 cald_hal_qct.c (2847) 9289 P [HAL] 381208648 - Cald_Hal_Qct_If_PowerUp (0)
I/caladbolg( 4185): 381218536 cald_camctrl.c (7563) 9289 P [SVR] 381218475 - Cald_CamCtrl_FSM_Func_PowerUp (0)
I/caladbolg( 4185): 381218933 cald_camctrl.c (6720) 9289 P [SVR] 381218902 - Cald_CamCtrl_PowerUp (0)
I/AwesomePlayer( 4185): setDataSource_l('/system/media/audio/ui/camera_click.ogg')
W/WVMExtractor( 4185): Failed to open libwvm.so
I/AwesomePlayer( 4185): setDataSource_l('/system/media/audio/ui/VideoRecord.ogg')
W/WVMExtractor( 4185): Failed to open libwvm.so
D/Camera ( 9175): app passed NULL surface
I/caladbolg( 4185): 381951782 cald_capctrl.c (6128) 9291 P [CAP] 381951751 + Cald_CapCtrl_FSM_Func_StartPreview
I/caladbolg( 4185): 381954376 cald_hal_qct.c (2983) 9291 P [HAL] 381954345 + Cald_Hal_Qct_If_StartPreview
I/caladbolg( 4185): 382005187 cald_hal_qct.c (3042) 9291 P [HAL] 382005157 - Cald_Hal_Qct_If_StartPreview (0)
I/caladbolg( 4185): 382005432 cald_capctrl.c (6358) 9291 P [CAP] 382005432 - Cald_CapCtrl_FSM_Func_StartPreview
F/libc ( 4185): Fatal signal 11 (SIGSEGV) at 0x00008f28 (code=1), thread 9298 (cam_conf)
I/DEBUG ( 132): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
I/DEBUG ( 132): Build fingerprint: 'SEMC/MT11i_1254-2184/MT11i:4.0.4/4.1.B.0.431/UL5_3w:user/release-keys'
I/DEBUG ( 132): pid: 4185, tid: 9298, name: UNKNOWN >>> /system/bin/mediaserver <<<
I/DEBUG ( 132): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 00008f28
I/ActivityManager( 362): Process com.cyanogenmod.filemanager (pid 7528) has died.
I/DEBUG ( 132): r0 2bb55c98 r1 00008e00 r2 2bb56800 r3 00000000
I/DEBUG ( 132): r4 2bb608fc r5 2bb1892c r6 2bb54f50 r7 2d3469cc
I/DEBUG ( 132): r8 2d346a58 r9 2d346a5c sl ffffffff fp 2d346c80
I/DEBUG ( 132): ip 2bb1897c sp 2d3469c8 lr 2bb0dc5b pc 2bb08578 cpsr 00010030
I/DEBUG ( 132): d0 0000000000000000 d1 0000000000000000
I/DEBUG ( 132): d2 0000000000000000 d3 0000000000000000
I/DEBUG ( 132): d4 0000000001e00000 d5 0000000000000000
I/DEBUG ( 132): d6 0007080000000000 d7 3f8000003f800000
I/DEBUG ( 132): d8 0000000000000000 d9 0000000000000000
I/DEBUG ( 132): d10 0000000000000000 d11 0000000000000000
I/DEBUG ( 132): d12 0000000000000000 d13 0000000000000000
I/DEBUG ( 132): d14 0000000000000000 d15 0000000000000000
I/DEBUG ( 132): d16 3a64696f72646e61 d17 7265676775626564
I/DEBUG ( 132): d18 bfe0000000000000 d19 0000000000000000
I/DEBUG ( 132): d20 0000000000000000 d21 0000000000000000
I/DEBUG ( 132): d22 0000000000000000 d23 0000000000000000
I/DEBUG ( 132): d24 3ff55d890c229271 d25 3fd8000000000000
I/DEBUG ( 132): d26 400170a260000000 d27 40020307a0000000
I/DEBUG ( 132): d28 4003ba2980000000 d29 400150da20000000
I/DEBUG ( 132): d30 4003ba2980000000 d31 40055815a0000000
I/DEBUG ( 132): scr 20000012
I/DEBUG ( 132):
I/DEBUG ( 132): backtrace:
I/DEBUG ( 132): #00 pc 00045578 /system/lib/liboemcamera.so (vfe_cmd_sharpnessscale+27)
I/DEBUG ( 132): #01 pc 0004ac57 /system/lib/liboemcamera.so (vfe_util_update_asf_5x5+30)
I/DEBUG ( 132): #02 pc 0004af9b /system/lib/liboemcamera.so (vfe_util_sharpness_afilter+2)
I/DEBUG ( 132): #03 pc 00040701 /system/lib/liboemcamera.so (vfe_process_VFE_ID_SOF_ACK+44)
I/DEBUG ( 132): #04 pc 0003d06b /system/lib/liboemcamera.so (vfe_proc_vfe_msg+74)
I/DEBUG ( 132): #05 pc 0000c77d /system/lib/liboemcamera.so (config_proc_vfe_event_message+12)
I/DEBUG ( 132): #06 pc 0000c43b /system/lib/liboemcamera.so (cam_conf+314)
I/DEBUG ( 132): #07 pc 000130d4 /system/lib/libc.so (__thread_entry+48)
I/DEBUG ( 132): #08 pc 0001283c /system/lib/libc.so (pthread_create+180)
Apparently the things crashes right after trying to open camera 1.
Unlike the rest of the civilized world, the computing area starts numbering with zero, so there's no doubt Instagram is trying to use the second (implying less important) camera - the face-facing one we already know is broken!
Cause found, how about the fix?
I suppose I could just clean the app's settings, but that's a too crude a measure for a 21st century gentleman.
A bit of searching reveals the file
/data/data/com.instagram.android/shared_prefs/com.instagram.android_preferences.xml
sports a very interesting line:
<string name="pref_camera_id_key">1</string>
Flip the 1 to a zero:
<string name="pref_camera_id_key">0</string>
and viola!
... eh, voilà!
This fixed it.