Failing to check for AMD processor microcode upgrades

[korrat]

Whenever I run needrestart (version 3.6) on my machine with an AMD processor, I get the message Failed to check for processor microcode upgrades.

sudo needrestart -v -w output:

[main] eval /etc/needrestart/needrestart.conf
[main] needrestart v3.6
[main] running in root mode
[Core] Using UI 'NeedRestart::UI::stdio'...
[main] systemd detected
[ucode] using NeedRestart::uCode::AMD
[ucode] using NeedRestart::uCode::Intel
[uCode/AMD] #0 cpuid 0x00860f01  (/dev/cpu/0/cpuid)
[uCode/AMD] #0 cpuid 0x00860f01  (/proc/cpuinfo)
[uCode/AMD] #0 running ucode 0x08600103
Use of uninitialized value $processor in concatenation (.) or string at /usr/share/perl5/vendor_perl/NeedRestart/uCode.pm line 61.
[ucode] # did not get available microcode version
[uCode/Intel] #0 current revision: 0x8600103
+ iucode_tool --scan-system
+ grep -oE [^[:space:]]+$
+ sig=processor
+ [ -r /sys/devices/system/cpu/cpu0/microcode/processor_flags ]
+ cat /sys/devices/system/cpu/cpu0/microcode/processor_flags
+ filter=-s processor,0x0
+ test -r /etc/needrestart/iucode.sh
+ . /etc/needrestart/iucode.sh
+ type bsdtar
+ imgfiles=
+ [ -r /boot/intel-ucode.img ]
+ [ -r /boot/early_ucode.cpio ]
+ [ -n  ]
+ IUCODE_TOOL_EXTRA_OPTIONS=
+ test -r /etc/default/intel-microcode
+ test  = no
+ [ -r /usr/share/misc/intel-microcode* ]
+ iucode_tool -l -s processor,0x0 --ignore-broken -tb /lib/firmware/intel-ucode
+ grep processor
Use of uninitialized value $processor in concatenation (.) or string at /usr/share/perl5/vendor_perl/NeedRestart/uCode.pm line 61.
[ucode] # did not get available microcode version

Failed to check for processor microcode upgrades.