make check is failing

[ixti]

Description

Running make check fails

Steps To Reproduce

Steps to reproduce the bug:

1. clone the repo
2. run make check

Expected Behavior

All checks should pass

Actual Behavior

Fails with lots of shellcheck errors

[postmodern]

I disabled many of the erroneous ShellCheck rules that were giving false positives, and fixed a few legitimate issues as well. Feel free to help out with the remaining linting errors.

In share/ruby-install/checksums.sh line 33:
    local output="$(grep "  $file" "$checksums")"
              ^----^ SC2155: Declare and assign separately to avoid masking return values.

In share/ruby-install/checksums.sh line 58:
    local output="$($program "$file")"
              ^----^ SC2155: Declare and assign separately to avoid masking return values.

In share/ruby-install/checksums.sh line 74:
    local actual_checksum="$(compute_checksum "$algorithm" "$file")"
              ^-------------^ SC2155: Declare and assign separately to avoid masking return values.

In share/ruby-install/functions.sh line 22:
    ruby_dependencies=($(fetch "$ruby/$file" "$package_manager" || return $?))
                           ^-- SC2207: Prefer mapfile or read -a to split command output (or quote to avoid splitting).

In share/ruby-install/package_manager.sh line 32:
            local brew_owner="$(/usr/bin/stat -f %Su "$(command -v brew)")"
                              ^--------^ SC2155: Declare and assign separately to avoid masking return values.

In share/ruby-install/package_manager.sh line 43:
            local missing_pkgs=($(pacman -T "$@"))
                                            ^---------------^ SC2207: Prefer mapfile or read -a to split command output (or quote to avoid splitting).

In share/ruby-install/ruby-install.sh line 275:
    local fully_qualified_version="$(lookup_ruby_version "$ruby" "$ruby_version")"
              ^---------------------^ SC2155: Declare and assign separately to avoid masking return values.

For more information:
  https://www.shellcheck.net/wiki/SC2155 -- Declare and assign separately to ...
  https://www.shellcheck.net/wiki/SC2207 -- Prefer mapfile or read -a to spli...

[ixti]

Opened a PR with fixes to the above linting errors.