What is amvault really telling me?

I am using the stock AMANDA packages on an Ubuntu 18.04 system: 3.5.1.  I am 
getting this error message from amvault:

backup@sauron:~$ /usr/sbin/amvault --dest-storage vault_changer --src-timestamp 20210404001017 deepsoft-vault
Storage 'vault_changer' not found
amreport: RuntimeError Usage: debug(msg); at /usr/lib/x86_64-linux-gnu/amanda/perl/Amanda/Report/human.pm line 439.

backup@sauron:~$ cat /etc/amanda/deepsoft-vault/amanda.conf 
includefile "/etc/amanda/deepsoft-normal/amanda.conf"

vault-storage "vault_changer"

autolabel "deepsoft-vault-%%%" volume-error empty
backup@sauron:~$ cat /etc/amanda/deepsoft-normal/amanda.conf
includefile "/etc/amanda/deepsoft-common/amanda.conf"
define tapetype HARDDISK {
    comment "Virtual Tapes"
    part_size 1432 mbytes
    part_cache_type none
    length 4300 mbytes
}

tapetype HARDDISK 


runtapes 20             # number of tapes to be used in a single run of amdump

And in /etc/amanda/deepsoft-common/amanda.conf I have:

define changer vault_changer {
    tpchanger "chg-disk:/backupdisk/deepsoft_vault/slots"
    changerfile "/etc/amanda/deepsoft-common/vault_changer"
    property "num-slot" "30"
}

What am I missing?

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