[Miscellaneous Android Development] katinatez:
So I unpacked your recovery here is your recovery.fstab

# mount point	fstype device	[device2]

#cat /proc/mtd
#dev: size erasesize name
#mtd0: 00100000 00040000 "misc"
#mtd1: 00500000 00040000 "recovery"
#mtd2: 00400000 00040000 "boot"
#mtd3: 0eb40000 00040000 "system"
#mtd4: 03b00000 00040000 "cache"
#mtd5: 09600000 00040000 "userdata"
#mtd6: 00a00000 00040000 "addon"

#mount
#/dev/block/mtdblock3 on /system type yaffs2 (ro,noatime,nodiratime)
#/dev/block/mtdblock5 on /data type yaffs2 (rw,nosuid,nodev,noatime,nodiratime)

/boot emmc boot	/dev/block/platform/sdhci-tegra.3/by-name/LNX
/cache ext4 cache /dev/block/platform/sdhci-tegra.3/by-name/CAC
/data ext4 data /dev/block/platform/sdhci-tegra.3/by-name/UDA	length=-32768
/misc emmc misc	/dev/block/platform/sdhci-tegra.3/by-name/MSC
/recovery emmc recovery	/dev/block/platform/sdhci-tegra.3/by-name/SOS
/sdcard ext4 sdcard /dev/block/mmcblk0p11
/system ext4 system /dev/block/platform/sdhci-tegra.3/by-name/APP
/sd-ext vfat sd-ext /dev/block/platform/sdhci-tegra.0/by-num/p1 flags=display="Micro SDcard";wipeingui;removable
/addon ext4 addon /dev/block/platform/sdhci-tegra.3/by-name/UDB flags=backup=1;display="Addon"
#/foreever ext4 forever /dev/block/mmcblk0p9
/devlog mtd devlog	/dev/block/mtdblock6

Try changing your recovery.fstab like my bacon device fstab

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/dev/block/platform/msm_sdcc.1/by-name/system /system ext4 ro,barrier=1 wait
/dev/block/platform/msm_sdcc.1/by-name/userdata /data ext4 noatime,nosuid,nodev,barrier=1,data=ordered,noauto_da_alloc,errors=panic wait,check,encryptable=/dev/block/platform/msm_sdcc.1/by-name/reserve4
/dev/block/platform/msm_sdcc.1/by-name/cache /cache ext4 noatime,nosuid,nodev,barrier=1,data=ordered,noauto_da_alloc,errors=panic wait,check
/dev/block/platform/msm_sdcc.1/by-name/persist /persist ext4 nosuid,nodev,barrier=1,data=ordered,nodelalloc,nomblk_io_submit,errors=panic wait
/dev/block/platform/msm_sdcc.1/by-name/boot /boot emmc defaults defaults
/dev/block/platform/msm_sdcc.1/by-name/recovery /recovery emmc defaults defaults
/dev/block/platform/msm_sdcc.1/by-name/misc /misc emmc defaults defaults
/dev/block/platform/msm_sdcc.1/by-name/modem /firmware vfat ro,shortname=lower,uid=1000,gid=1026,dmask=227,fmask=337,context=u:object_r:firmware_file:s0 wait

/dev/block/platform/msm_sdcc.1/by-name/modemst1 /efs1 emmc default defaults
/dev/block/platform/msm_sdcc.1/by-name/modemst2 /efs2 emmc default defaults

/devices/platform/xhci-hcd auto auto defaults voldmanaged=usbdisk:auto

Then compile again, I am a little past noob, learned how to compile Philz recovery to maintain One Plus One phone, I got roasted by Phil for using twrp flags, and fstab style on a cwm build just sharing the knowledge; no roasting . Its easier to build on a device with a working device tree. Also I meant for you to send your mt799 entire directory files not the compiled recovery as I am having compiling errors on one of my make files. Hope this helps you