In /usr/bin/libgcrypt-config line 20: gpg_error_libs="-L/usr/lib/x86_64-linux-gnu -lgpg-error" ^------------^ SC2034: gpg_error_libs appears unused. Verify use (or export if used externally). In /usr/bin/libgcrypt-config line 63: exit $1 ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: exit "$1" In /usr/bin/libgcrypt-config line 75: optarg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` ^-- SC2006: Use $(...) notation instead of legacy backticked `...`. Did you mean: optarg=$(echo "$1" | sed 's/[-_a-zA-Z0-9]*=//') In /usr/bin/libgcrypt-config line 78: optarg="" ^----^ SC2034: optarg appears unused. Verify use (or export if used externally). In /usr/bin/libgcrypt-config line 145: if echo "$tmp" | fgrep -v -- "$i" >/dev/null; then ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/libgcrypt-config line 149: echo $tmp ^--^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: echo "$tmp" In /usr/bin/libgcrypt-config line 155: debianmultiarch=`if which dpkg-architecture > /dev/null ; then dpkg-architecture -qDEB_HOST_MULTIARCH ; fi` ^-- SC2006: Use $(...) notation instead of legacy backticked `...`. Did you mean: debianmultiarch=$(if which dpkg-architecture > /dev/null ; then dpkg-architecture -qDEB_HOST_MULTIARCH ; fi) In /usr/bin/libgcrypt-config line 168: if echo "$tmp" | fgrep -v -- "$i" >/dev/null; then ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/libgcrypt-config line 172: echo $tmp ^--^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: echo "$tmp" For more information: https://www.shellcheck.net/wiki/SC2034 -- gpg_error_libs appears unused. Ve... https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ... https://www.shellcheck.net/wiki/SC2197 -- fgrep is non-standard and depreca...