platform_manifest_twrp_omni/twrp-extras.xml

<?xml version="1.0" encoding="UTF-8"?>
<manifest>
    <remote name="TeamWin"
            fetch="https://github.com/TeamWin"
            review="https://gerrit.twrp.me" />

    <remote name="LineageOS"
            fetch="https://github.com/LineageOS"
            review="https://review.lineageos.org" />

<!-- TWRP lives in TeamWin repo, not OmniROM -->
    <remove-project name="android_bootable_recovery" />
    <project path="bootable/recovery" name="android_bootable_recovery" remote="TeamWin" revision="android-9.0" />

<!-- Include forked external unzip repo from CyanogenMod for toolbox/toybox support -->
    <project path="external/unzip" name="android_external_unzip" remote="TeamWin" revision="cm-14.1" />

<!-- Include external zip repo for zip support -->
    <project path="external/zip" name="android_external_zip" remote="TeamWin" revision="android-7.1" />

<!-- Include external LineageOS repos for bash & nano -->
    <project name="android_external_bash" path="external/bash" remote="LineageOS" revision="cm-14.1" />
    <project name="android_external_nano" path="external/nano" remote="LineageOS" revision="cm-14.1" />
    <project name="android_external_libncurses" path="external/libncurses" remote="LineageOS" revision="cm-14.1" />
</manifest>