Cannot set EFI variable Boot0000. No space left on device

Question

I have a dual-boot of Debian 9 with the grub bootloader that I'm trying to upgrade to Debian 10. The steps I've taken so far are going through are here. The step it failed on was after I updated and upgraded my Debian 9 packages. I then updated my sources to for Debian 10 and did an update, upgrade, and it fails on full-upgrade. It fails trying to process:

minisspd
shim-signed-common
shim-signed:amd64

The full output is here:

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
3 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] 
Setting up minissdpd (1.5.20190210-1) ...
docker0 wlp2s0 Job for minissdpd.service failed because the control process exited with error code.
See "systemctl status minissdpd.service" and "journalctl -xe" for details.
invoke-rc.d: initscript minissdpd, action "restart" failed.
● minissdpd.service - keep memory of all UPnP devices that announced themselves
   Loaded: loaded (/lib/systemd/system/minissdpd.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Mon 2021-01-04 21:25:44 EST; 5ms ago
     Docs: man:minissdpd(1)
  Process: 27453 ExecStart=/usr/lib/minissdpd/minissdpd-systemd-wrapper ${MiniSSDPd_INTERFACE_ADDRESS} $MiniSSDPd_OTHER_OPTIONS (code=exited, status=1/FAILURE)

Jan 04 21:25:44 surya-debian systemd[1]: Starting keep memory of all UPnP devices that announced themselves...
Jan 04 21:25:44 surya-debian minissdpd-systemd-wrapper[27453]: Usage: /usr/sbin/minissdpd [-d] [-6] [-s socket] [-p pidfile] [-t TTL] [-f device] -i <interface> [-i <interface2>] ...
Jan 04 21:25:44 surya-debian minissdpd-systemd-wrapper[27453]:   <interface> is either an IPv4 address with mask such as
Jan 04 21:25:44 surya-debian minissdpd-systemd-wrapper[27453]:   192.168.1.42/255.255.255.0, or an interface name such as eth0.
Jan 04 21:25:44 surya-debian minissdpd-systemd-wrapper[27453]:   By default, socket will be open as /var/run/minissdpd.sock
Jan 04 21:25:44 surya-debian minissdpd-systemd-wrapper[27453]:   and pid written to file /var/run/minissdpd.pid
Jan 04 21:25:44 surya-debian systemd[1]: minissdpd.service: Control process exited, code=exited, status=1/FAILURE
Jan 04 21:25:44 surya-debian systemd[1]: minissdpd.service: Failed with result 'exit-code'.
Jan 04 21:25:44 surya-debian systemd[1]: Failed to start keep memory of all UPnP devices that announced themselves.
dpkg: error processing package minissdpd (--configure):
 installed minissdpd package post-installation script subprocess returned error exit status 1
Setting up shim-signed-common (1.33+15+1533136590.3beb971-7) ...
Installing for x86_64-efi platform.
grub-install: warning: Cannot set EFI variable Boot0000.
grub-install: warning: efivarfs_set_variable: writing to fd 8 failed: No space left on device.
grub-install: warning: _efi_set_variable_mode: ops->set_variable() failed: No space left on device.
grub-install: error: failed to register the EFI boot entry: No space left on device.
dpkg: error processing package shim-signed-common (--configure):
 installed shim-signed-common package post-installation script subprocess returned error exit status 1
dpkg: dependency problems prevent configuration of shim-signed:amd64:
 shim-signed:amd64 depends on shim-signed-common (= 1.33+15+1533136590.3beb971-7); however:
  Package shim-signed-common is not configured yet.

dpkg: error processing package shim-signed:amd64 (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 minissdpd
 shim-signed-common
 shim-signed:amd64
E: Sub-process /usr/bin/dpkg returned an error code (1)

I've already tried clearing with rm /sys/firmware/efi/efivars/dump-* but no luck. Not sure what the problem could be. I dfd my partitions:

Filesystem            Size  Used Avail Use% Mounted on
udev                  3.8G     0  3.8G   0% /dev
tmpfs                 776M   39M  737M   5% /run
/dev/nvme0n1p6        134G  116G   12G  92% /
tmpfs                 3.8G  358M  3.5G  10% /dev/shm
tmpfs                 5.0M  4.0K  5.0M   1% /run/lock
tmpfs                 3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/nvme0n1p1        256M   36M  221M  14% /boot/efi
tmpfs                 776M   24K  775M   1% /run/user/117
tmpfs                 776M   32K  775M   1% /run/user/1000
/home/<my-username>/.Private  134G  116G   12G  92% /home/<my-username>/Private

and it looks like the /boot/efi partition has less than 50% space available which I've heard causes problems, but not sure what to do about it.

Update: Resolved

Turns out all I had to do was reboot after clearing the dump files in /sys/firmware/efi/efivars/dump-*. Running apt full-upgrade afterwards resolved the shim* problems. Still have a minissdpd issue but it seems far more benign and not related.

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