In /usr/bin/which-pkg-broke-build line 19:
    echo -n "build-essential "
         ^-- SC2039: In POSIX sh, echo flags are undefined.


In /usr/bin/which-pkg-broke-build line 23:
        cat debian/control | sed ':a;N;$!ba;s/\(Build-Depends[^ ]*:[^\n:]*\)\n/\1 /g'
            ^------------^ SC2002: Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead.


In /usr/bin/which-pkg-broke-build line 25:
        fgrep Build-Depends | \
        ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead.


In /usr/bin/which-pkg-broke-build line 32:
    which-pkg-broke $pkg
                    ^--^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    which-pkg-broke "$pkg"


In /usr/bin/which-pkg-broke-build line 34:
    fgrep -v "has no install time info" | \
    ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead.


In /usr/bin/which-pkg-broke-build line 35:
    while read pkg date; do
          ^--^ SC2162: read without -r will mangle backslashes.


In /usr/bin/which-pkg-broke-build line 36:
        echo `date +%s -d "$date"` $pkg
             ^-------------------^ SC2046: Quote this to prevent word splitting.
             ^-------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                                   ^--^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
        echo $(date +%s -d "$date") "$pkg"


In /usr/bin/which-pkg-broke-build line 40:
    while read date pkg; do
          ^--^ SC2162: read without -r will mangle backslashes.


In /usr/bin/which-pkg-broke-build line 41:
        echo $pkg `date +"%x %X" -d "@$date"`
             ^--^ SC2086: Double quote to prevent globbing and word splitting.
                  ^-------------------------^ SC2046: Quote this to prevent word splitting.
                  ^-------------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
        echo "$pkg" $(date +"%x %X" -d "@$date")

For more information:
  https://www.shellcheck.net/wiki/SC2039 -- In POSIX sh, echo flags are undef...
  https://www.shellcheck.net/wiki/SC2046 -- Quote this to prevent word splitt...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...