Creating initramfs fails on blkid

/dev/sda is an external SD card (root is /dev/nvme0n1)

==> initramfs: creating /boot/initramfs-postmarketos-rockchip-extra
(006938) [16:34:29]  *** SET LOGIN PASSWORD FOR: 'me' ***
(006938) [16:34:29] (rootfs_pine64-pinebookpro) % passwd me
New password: 
Retype new password: 
passwd: password updated successfully
(006938) [16:34:36] (rootfs_pine64-pinebookpro) % passwd -l root
passwd: password expiry information changed.
(006938) [16:34:36] NOTE: No valid keymap specified for device
(006938) [16:34:36] (rootfs_pine64-pinebookpro) % setup-timezone -z America/New_York
(006938) [16:34:39] (rootfs_pine64-pinebookpro) % sh -c echo myhostname > /etc/hostname
(006938) [16:34:39] (rootfs_pine64-pinebookpro) % sed -i -e s/^127\.0\.0\.1.*/127.0.0.1\tmyhostname localhost.localdomain localhost/ /etc/hosts
(006938) [16:34:39] *** (3/5) PREPARE INSTALL BLOCKDEVICE ***
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/var/cache/distfiles
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/var/cache/apk
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/usr/bin/qemu-aarch64-static
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/proc
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/mnt/pmbootstrap-rust
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/mnt/pmbootstrap-packages
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/mnt/pmbootstrap-git
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/mnt/pmbootstrap-ccache
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/mnt/pmbootstrap-abuild-config
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/etc/apk/keys
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/dev/shm
(006938) [16:34:39] % sudo umount /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro/dev
(006938) [16:34:39] % sudo du --summarize --block-size=1 /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro
642113536       /home/me/.local/var/pmbootstrap/chroot_rootfs_pine64-pinebookpro

(006938) [16:34:39] (native) mount /dev/install (host: /dev/sda)
(006938) [16:34:39] % sudo touch /home/me/.local/var/pmbootstrap/chroot_native/dev/install
(006938) [16:34:39] % sudo mount --bind /dev/sda /home/me/.local/var/pmbootstrap/chroot_native/dev/install
(006938) [16:34:39] % sudo touch /home/me/.local/var/pmbootstrap/chroot_native/dev/sdcardp1
(006938) [16:34:39] % sudo mount --bind /dev/sda1 /home/me/.local/var/pmbootstrap/chroot_native/dev/sdcardp1
(006938) [16:34:39] (native) % blkid -s LABEL -o value /dev/sdcardp1
(006938) [16:34:39] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(006938) [16:34:39] NOTE: The failed command's output is above the ^^^ line in the log file: /home/me/.local/var/pmbootstrap/log.txt
(006938) [16:34:39] ERROR: Command failed: (native) % blkid -s LABEL -o value /dev/sdcardp1
(006938) [16:34:39] See also: <https://postmarketos.org/troubleshooting>
(006938) [16:34:39] Traceback (most recent call last):
  File "/home/me/pmbootstrap/pmb/__init__.py", line 49, in main
    getattr(frontend, args.action)(args)
  File "/home/me/pmbootstrap/pmb/helpers/frontend.py", line 268, in install
    pmb.install.install(args)
  File "/home/me/pmbootstrap/pmb/install/_install.py", line 691, in install
    install_system_image(args, 0, f"rootfs_{args.device}",
  File "/home/me/pmbootstrap/pmb/install/_install.py", line 445, in install_system_image
    pmb.install.blockdevice.create(args, size_boot, size_root,
  File "/home/me/pmbootstrap/pmb/install/blockdevice.py", line 134, in create
    mount_sdcard(args, sdcard)
  File "/home/me/pmbootstrap/pmb/install/blockdevice.py", line 49, in mount_sdcard
    if previous_install(args, path):
  File "/home/me/pmbootstrap/pmb/install/blockdevice.py", line 26, in previous_install
    label = pmb.chroot.root(args, ["blkid", "-s", "LABEL", "-o", "value",
  File "/home/me/pmbootstrap/pmb/chroot/root.py", line 74, in root
    return pmb.helpers.run_core.core(args, msg, cmd_sudo, None, output,
  File "/home/me/pmbootstrap/pmb/helpers/run_core.py", line 285, in core
    raise RuntimeError("Command failed: " + log_message)
RuntimeError: Command failed: (native) % blkid -s LABEL -o value /dev/sdcardp1