In /logs/firmware/patool_extraction/rootfs.img_unblob_extracted/rootfs.img_extract/0-50593792.squashfs_v4_le_extract/usr/share/serverreport.d/mqtt_config.sh line 3:

. /lib/rcscripts/sh/error.sh

  ^------------------------^ SC1091 (info): Not following: /lib/rcscripts/sh/error.sh was not specified as input (see shellcheck -x).

In /logs/firmware/patool_extraction/rootfs.img_unblob_extracted/rootfs.img_extract/0-50593792.squashfs_v4_le_extract/usr/share/serverreport.d/mqtt_config.sh line 5:

. $rc || error "Failed to source '$rc'"

  ^-^ SC1090 (warning): ShellCheck can't follow non-constant source. Use a directive to specify location.

In /logs/firmware/patool_extraction/rootfs.img_unblob_extracted/rootfs.img_extract/0-50593792.squashfs_v4_le_extract/usr/share/serverreport.d/mqtt_config.sh line 9:

for f in /etc/mqtt-client/__default__client.conf; do

         ^-- SC2043 (warning): This loop will only ever run once. Bad quoting or missing glob/expansion?

In /logs/firmware/patool_extraction/rootfs.img_unblob_extracted/rootfs.img_extract/0-50593792.squashfs_v4_le_extract/usr/share/serverreport.d/mqtt_config.sh line 24:

echo [status]

     ^------^ SC2102 (info): Ranges can only match single chars (mentioned due to duplicates).

In /logs/firmware/patool_extraction/rootfs.img_unblob_extracted/rootfs.img_extract/0-50593792.squashfs_v4_le_extract/usr/share/serverreport.d/mqtt_config.sh line 25:

echo Client status: $state

                    ^----^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

echo Client status: "$state"

In /logs/firmware/patool_extraction/rootfs.img_unblob_extracted/rootfs.img_extract/0-50593792.squashfs_v4_le_extract/usr/share/serverreport.d/mqtt_config.sh line 26:

echo Connection status: $connection

                        ^---------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

echo Connection status: "$connection"

For more information:

  https://www.shellcheck.net/wiki/SC1090 -- ShellCheck can't follow non-const...

  https://www.shellcheck.net/wiki/SC2043 -- This loop will only ever run once...

  https://www.shellcheck.net/wiki/SC1091 -- Not following: /lib/rcscripts/sh/...