In /usr/bin/whodepends line 9:
PROGNAME=`basename $0`
         ^-----------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                   ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
PROGNAME=$(basename "$0")


In /usr/bin/whodepends line 41:
			for package in `apt-cache showpkg $1 | sed -n '/Reverse Depends:/,/Dependencies/p' | grep '^ '|sed 's/,.*//'`; do
                                       ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.
                                                          ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
			for package in $(apt-cache showpkg "$1" | sed -n '/Reverse Depends:/,/Dependencies/p' | grep '^ '|sed 's/,.*//'); do


In /usr/bin/whodepends line 43:
					apt-cache showsrc $package |
                                                          ^------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
					apt-cache showsrc "$package" |


In /usr/bin/whodepends line 47:
					apt-cache show $package |
                                                       ^------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
					apt-cache show "$package" |


In /usr/bin/whodepends line 48:
					awk '/^Maintainer:/ {maint=$0} END {print maint, "'$package'"}' |
                                                                                           ^------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
					awk '/^Maintainer:/ {maint=$0} END {print maint, "'"$package"'"}' |

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...