Pushing to TWRP, adb shows "adb: error: connect failed: no devices/emulators found" When I try to push my rom to /sdcard/ with TWRP, I get

adb push myRom.zip /sdcard/
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
adb: error: connect failed: no devices/emulators found


How do I resolve this error. Things seem to work with  adb sideload but the rom doesn't boot. The LineageOS install instructions say specifically to use with adb push.
Try killing the process and then retrying:

adb kill-server
adb push myRom.zip /sdcard/