diff --git a/Dockerfile b/Dockerfile
index a21299e6..397277d9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,6 +10,8 @@ ENV PACKAGES="\
     git \
     python \
     py-pip \
+    grep \
+    sed \
 "
 RUN apk --update add $PACKAGES && \
     rm -rf /var/cache/apk/* /tmp/* /var/tmp/*
diff --git a/doc/ale-supported-languages-and-tools.txt b/doc/ale-supported-languages-and-tools.txt
index b0efb2bb..ccedd2ad 100644
--- a/doc/ale-supported-languages-and-tools.txt
+++ b/doc/ale-supported-languages-and-tools.txt
@@ -49,8 +49,8 @@ Notes:
   * `astyle`
   * `ccls`
   * `clang` (`cc`)
-  * `clangd`
   * `clang-format`
+  * `clangd`
   * `clangtidy`!!
   * `cppcheck`
   * `cpplint`!!
@@ -67,9 +67,9 @@ Notes:
   * `astyle`
   * `ccls`
   * `clang` (`cc`)
+  * `clang-format`
   * `clangcheck`!!
   * `clangd`
-  * `clang-format`
   * `clangtidy`!!
   * `clazy`!!
   * `cppcheck`
@@ -140,9 +140,9 @@ Notes:
   * `erubis`
   * `ruumba`
 * Erlang
+  * `SyntaxErl`
   * `elvis`!!
   * `erlc`
-  * `SyntaxErl`
 * Fish
   * `fish` (-n flag)
 * Fortran
@@ -160,17 +160,17 @@ Notes:
 * Go
   * `bingo`
   * `go build`!!
+  * `go mod`!!
+  * `go vet`!!
   * `gofmt`
   * `goimports`
   * `golangci-lint`!!
   * `golangserver`
   * `golint`
   * `gometalinter`!!
-  * `go mod`!!
   * `gopls`
   * `gosimple`!!
   * `gotype`!!
-  * `go vet`!!
   * `revive`!!
   * `staticcheck`!!
 * GraphQL
@@ -203,10 +203,10 @@ Notes:
 * HCL
   * `terraform-fmt`
 * HTML
+  * `HTMLHint`
   * `alex`!!
   * `fecs`
   * `html-beautify`
-  * `HTMLHint`
   * `prettier`
   * `proselint`
   * `tidy`
@@ -220,12 +220,12 @@ Notes:
 * ISPC
   * `ispc`!!
 * Java
+  * `PMD`
   * `checkstyle`
   * `eclipselsp`
   * `google-java-format`
   * `javac`
   * `javalsp`
-  * `PMD`
   * `uncrustify`
 * JavaScript
   * `eslint`
@@ -332,10 +332,10 @@ Notes:
   * `intelephense`
   * `langserver`
   * `phan`
+  * `php -l`
+  * `php-cs-fixer`
   * `phpcbf`
   * `phpcs`
-  * `php-cs-fixer`
-  * `php -l`
   * `phpmd`
   * `phpstan`
   * `psalm`!!
@@ -396,6 +396,8 @@ Notes:
   * `styler`
 * Racket
   * `raco`
+* Re:VIEW
+  * `redpen`
 * ReasonML
   * `merlin`
   * `ols`
@@ -409,8 +411,6 @@ Notes:
   * `textlint`
   * `vale`
   * `write-good`
-* Re:VIEW
-  * `redpen`
 * RPM spec
   * `rpmlint`
 * Ruby
@@ -457,10 +457,10 @@ Notes:
   * `solium`
 * SQL
   * `pgformatter`
+  * `sql-lint`
   * `sqlfmt`
   * `sqlformat`
   * `sqlint`
-  * `sql-lint`
 * Stylus
   * `stylelint`
 * SugarSS
diff --git a/doc/ale.txt b/doc/ale.txt
index a77407a1..c5e34c87 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -2991,11 +2991,11 @@ documented in additional help files.
     hdl-checker...........................|ale-vhdl-hdl-checker|
     vcom..................................|ale-vhdl-vcom|
     xvhdl.................................|ale-vhdl-xvhdl|
+  vim help................................|ale-vim-help-options|
+    write-good............................|ale-vim-help-write-good|
   vim.....................................|ale-vim-options|
     vimls.................................|ale-vim-vimls|
     vint..................................|ale-vim-vint|
-  vim help................................|ale-vim-help-options|
-    write-good............................|ale-vim-help-write-good|
   vue.....................................|ale-vue-options|
     prettier..............................|ale-vue-prettier|
     vls...................................|ale-vue-vls|
diff --git a/run-tests b/run-tests
index 1d452a72..cbd03af2 100755
--- a/run-tests
+++ b/run-tests
@@ -9,8 +9,8 @@ set -u
 # options, or read the output below.
 #
 
-image=w0rp/ale
-current_image_id=f58c7bf8900f
+image=akevinclark/ale
+current_image_id=8e1802ca34b5
 
 # Used in all test scripts for running the selected Docker image.
 DOCKER_RUN_IMAGE="$image"
diff --git a/supported-tools.md b/supported-tools.md
index 9e3e5087..7590e9a4 100644
--- a/supported-tools.md
+++ b/supported-tools.md
@@ -58,8 +58,8 @@ formatting.
   * [astyle](http://astyle.sourceforge.net/)
   * [ccls](https://github.com/MaskRay/ccls)
   * [clang](http://clang.llvm.org/)
-  * [clangd](https://clang.llvm.org/extra/clangd.html)
   * [clang-format](https://clang.llvm.org/docs/ClangFormat.html)
+  * [clangd](https://clang.llvm.org/extra/clangd.html)
   * [clangtidy](http://clang.llvm.org/extra/clang-tidy/) :floppy_disk:
   * [cppcheck](http://cppcheck.sourceforge.net)
   * [cpplint](https://github.com/google/styleguide/tree/gh-pages/cpplint)
@@ -76,9 +76,9 @@ formatting.
   * [astyle](http://astyle.sourceforge.net/)
   * [ccls](https://github.com/MaskRay/ccls)
   * [clang](http://clang.llvm.org/)
+  * [clang-format](https://clang.llvm.org/docs/ClangFormat.html)
   * [clangcheck](http://clang.llvm.org/docs/ClangCheck.html) :floppy_disk:
   * [clangd](https://clang.llvm.org/extra/clangd.html)
-  * [clang-format](https://clang.llvm.org/docs/ClangFormat.html)
   * [clangtidy](http://clang.llvm.org/extra/clang-tidy/) :floppy_disk:
   * [clazy](https://github.com/KDE/clazy) :floppy_disk:
   * [cppcheck](http://cppcheck.sourceforge.net)
@@ -149,9 +149,9 @@ formatting.
   * [erubis](https://github.com/kwatch/erubis)
   * [ruumba](https://github.com/ericqweinstein/ruumba)
 * Erlang
+  * [SyntaxErl](https://github.com/ten0s/syntaxerl)
   * [elvis](https://github.com/inaka/elvis) :floppy_disk:
   * [erlc](http://erlang.org/doc/man/erlc.html)
-  * [SyntaxErl](https://github.com/ten0s/syntaxerl)
 * Fish
   * fish [-n flag](https://linux.die.net/man/1/fish)
 * Fortran
@@ -169,17 +169,17 @@ formatting.
 * Go
   * [bingo](https://github.com/saibing/bingo) :warning:
   * [go build](https://golang.org/cmd/go/) :warning: :floppy_disk:
+  * [go mod](https://golang.org/cmd/go/) :warning: :floppy_disk:
+  * [go vet](https://golang.org/cmd/vet/) :floppy_disk:
   * [gofmt](https://golang.org/cmd/gofmt/)
   * [goimports](https://godoc.org/golang.org/x/tools/cmd/goimports) :warning:
   * [golangci-lint](https://github.com/golangci/golangci-lint) :warning: :floppy_disk:
   * [golangserver](https://github.com/sourcegraph/go-langserver) :warning:
   * [golint](https://godoc.org/github.com/golang/lint)
   * [gometalinter](https://github.com/alecthomas/gometalinter) :warning: :floppy_disk:
-  * [go mod](https://golang.org/cmd/go/) :warning: :floppy_disk:
   * [gopls](https://github.com/golang/go/wiki/gopls) :warning:
   * [gosimple](https://github.com/dominikh/go-tools/tree/master/cmd/gosimple) :warning: :floppy_disk:
   * [gotype](https://godoc.org/golang.org/x/tools/cmd/gotype) :warning: :floppy_disk:
-  * [go vet](https://golang.org/cmd/vet/) :floppy_disk:
   * [revive](https://github.com/mgechev/revive) :warning: :floppy_disk:
   * [staticcheck](https://github.com/dominikh/go-tools/tree/master/cmd/staticcheck) :warning: :floppy_disk:
 * GraphQL
@@ -212,10 +212,10 @@ formatting.
 * HCL
   * [terraform-fmt](https://github.com/hashicorp/terraform)
 * HTML
+  * [HTMLHint](http://htmlhint.com/)
   * [alex](https://github.com/wooorm/alex) :floppy_disk:
   * [fecs](http://fecs.baidu.com/)
   * [html-beautify](https://beautifier.io/)
-  * [HTMLHint](http://htmlhint.com/)
   * [prettier](https://github.com/prettier/prettier)
   * [proselint](http://proselint.com/)
   * [tidy](http://www.html-tidy.org/)
@@ -229,12 +229,12 @@ formatting.
 * ISPC
   * [ispc](https://ispc.github.io/) :floppy_disk:
 * Java
+  * [PMD](https://pmd.github.io/)
   * [checkstyle](http://checkstyle.sourceforge.net)
   * [eclipselsp](https://github.com/eclipse/eclipse.jdt.ls)
   * [google-java-format](https://github.com/google/google-java-format)
   * [javac](http://www.oracle.com/technetwork/java/javase/downloads/index.html)
   * [javalsp](https://github.com/georgewfraser/vscode-javac)
-  * [PMD](https://pmd.github.io/)
   * [uncrustify](https://github.com/uncrustify/uncrustify)
 * JavaScript
   * [eslint](http://eslint.org/)
@@ -341,10 +341,10 @@ formatting.
   * [intelephense](https://github.com/bmewburn/intelephense-docs)
   * [langserver](https://github.com/felixfbecker/php-language-server)
   * [phan](https://github.com/phan/phan) see `:help ale-php-phan` to instructions
+  * [php -l](https://secure.php.net/)
+  * [php-cs-fixer](http://cs.sensiolabs.org/)
   * [phpcbf](https://github.com/squizlabs/PHP_CodeSniffer)
   * [phpcs](https://github.com/squizlabs/PHP_CodeSniffer)
-  * [php-cs-fixer](http://cs.sensiolabs.org/)
-  * [php -l](https://secure.php.net/)
   * [phpmd](https://phpmd.org)
   * [phpstan](https://github.com/phpstan/phpstan)
   * [psalm](https://getpsalm.org) :floppy_disk:
@@ -405,6 +405,8 @@ formatting.
   * [styler](https://github.com/r-lib/styler)
 * Racket
   * [raco](https://docs.racket-lang.org/raco/)
+* Re:VIEW
+  * [redpen](http://redpen.cc/)
 * ReasonML
   * [merlin](https://github.com/the-lambda-church/merlin) see `:help ale-reasonml-ols` for configuration instructions
   * [ols](https://github.com/freebroccolo/ocaml-language-server)
@@ -418,8 +420,6 @@ formatting.
   * [textlint](https://textlint.github.io/)
   * [vale](https://github.com/ValeLint/vale)
   * [write-good](https://github.com/btford/write-good)
-* Re:VIEW
-  * [redpen](http://redpen.cc/)
 * RPM spec
   * [rpmlint](https://github.com/rpm-software-management/rpmlint) :warning: (see `:help ale-integration-spec`)
 * Ruby
@@ -466,10 +466,10 @@ formatting.
   * [solium](https://github.com/duaraghav8/Solium)
 * SQL
   * [pgformatter](https://github.com/darold/pgFormatter)
+  * [sql-lint](https://github.com/joereynolds/sql-lint)
   * [sqlfmt](https://github.com/jackc/sqlfmt)
   * [sqlformat](https://github.com/andialbrecht/sqlparse)
   * [sqlint](https://github.com/purcell/sqlint)
-  * [sql-lint](https://github.com/joereynolds/sql-lint)
 * Stylus
   * [stylelint](https://github.com/stylelint/stylelint)
 * SugarSS
diff --git a/test/script/check-duplicate-tags b/test/script/check-duplicate-tags
new file mode 100755
index 00000000..ec1de788
--- /dev/null
+++ b/test/script/check-duplicate-tags
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+set -e
+
+grep --exclude=tags -roh '\*.*\*$' doc | sort | uniq -d
diff --git a/test/script/check-supported-tools-tables b/test/script/check-supported-tools-tables
index f4305707..d238e77f 100755
--- a/test/script/check-supported-tools-tables
+++ b/test/script/check-supported-tools-tables
@@ -15,14 +15,13 @@ while read -r; do
     if [[ "$REPLY" =~ ^! ]]; then
         language="${REPLY/!/}"
     else
-        # shellcheck disable=SC2001
         echo "$language - $REPLY"
     fi
 done < <(
     grep '^\*\|^  *\*' doc/ale-supported-languages-and-tools.txt \
     | sed -e '1,2d' \
     | sed 's/^\* */!/' \
-    | sed 's/^ *\* *\|!!\|\^\|(.*)\|`//g' \
+    | sed -E 's/^ *\* *|!!|\^|\(.*\)|`//g' \
     | sed 's/ *$//'
 ) > "$doc_file"
 
@@ -30,13 +29,12 @@ while read -r; do
     if [[ "$REPLY" =~ ^! ]]; then
         language="${REPLY/!/}"
     else
-        # shellcheck disable=SC2001
         echo "$language - $REPLY"
     fi
 done < <(
     grep '^\*\|^  *\*' supported-tools.md \
     | sed 's/^\* */!/' \
-    | sed 's/^ *\* *\|:floppy_disk:\|:warning:\|(.*)\|\[\|\].*\|-n flag//g' \
+    | sed -E 's/^ *\* *|:floppy_disk:|:warning:|\(.*\)|\[|\].*|-n flag//g' \
     | sed 's/ *$//'
 ) > "$readme_file"
 
diff --git a/test/script/check-tag-alignment b/test/script/check-tag-alignment
new file mode 100755
index 00000000..d41db160
--- /dev/null
+++ b/test/script/check-tag-alignment
@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+exit_code=0
+
+# Documentation tags need to be aligned to the right margin, so look for
+# tags which aren't at the right margin.
+grep ' \*[^*]\+\*$' doc/ -r \
+    | awk '{ sep = index($0, ":"); if (length(substr($0, sep + 1 )) < 79) { print } }' \
+    | grep . && exit_code=1
+
+exit $exit_code
diff --git a/test/script/check-tag-references b/test/script/check-tag-references
new file mode 100755
index 00000000..45e741fb
--- /dev/null
+++ b/test/script/check-tag-references
@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+set -e
+
+exit_code=0
+tag_regex='[gb]\?:\?\(ale\|ALE\)[a-zA-Z_\-]\+'
+
+tags="$(mktemp -t tags.XXXXXXXX)"
+refs="$(mktemp -t refs.XXXXXXXX)"
+# Grep for tags and references, and complain if we find a reference without
+# a tag for the reference. Only our tags will be included.
+grep --exclude=tags -roh "\\*$tag_regex\\*" doc | sed 's/*//g' | sort -u > "$tags"
+grep --exclude=tags -roh "|$tag_regex|" doc | sed 's/|//g' | sort -u > "$refs"
+
+exit_code=0
+
+if ! [[ $(comm -23 $refs $tags | wc -l) -eq 0 ]]; then
+  exit_code=1
+fi
+
+rm "$tags"
+rm "$refs"
diff --git a/test/script/check-toc b/test/script/check-toc
index 87a61262..f3f8a9ea 100755
--- a/test/script/check-toc
+++ b/test/script/check-toc
@@ -35,7 +35,7 @@ sed -n "$toc_start_line,$toc_end_line"p doc/ale.txt \
     > "$toc_file"
 
 # Get all of the doc files in a natural sorted order.
-doc_files="$(/usr/bin/env ls -1v doc | grep ^ale- | sed 's/^/doc\//' | paste -sd ' ' -)"
+doc_files="$(/usr/bin/env ls -1v doc | grep '^ale-' | sed 's/^/doc\//' | paste -sd ' ' -)"
 
 # shellcheck disable=SC2086
 grep -h '\*ale-.*-options\|^[a-z].*\*ale-.*\*$' $doc_files \
diff --git a/test/script/custom-checks b/test/script/custom-checks
index ca9069e4..83afb28c 100755
--- a/test/script/custom-checks
+++ b/test/script/custom-checks
@@ -13,7 +13,7 @@ echo 'Custom warnings/errors follow:'
 echo
 
 set -o pipefail
-docker run -a stdout "${docker_flags[@]}" test/script/custom-linting-rules . || exit_code=$?
+docker run "${docker_flags[@]}" test/script/custom-linting-rules . || exit_code=$?
 set +o pipefail
 echo
 
@@ -23,7 +23,10 @@ echo '========================================'
 echo 'Duplicate tags follow:'
 echo
 
-grep --exclude=tags -roh '\*.*\*$' doc | sort | uniq -d || exit_code=$?
+set -o pipefail
+docker run "${docker_flags[@]}" test/script/check-duplicate-tags . || exit_code=$?
+set +o pipefail
+echo
 
 echo '========================================'
 echo 'Checking for invalid tag references'
@@ -31,14 +34,9 @@ echo '========================================'
 echo 'Invalid tag references tags follow:'
 echo
 
-tag_regex='[gb]\?:\?\(ale\|ALE\)[a-zA-Z_\-]\+'
-
-# Grep for tags and references, and complain if we find a reference without
-# a tag for the reference. Only our tags will be included.
-diff -u \
-    <(grep --exclude=tags -roh "\\*$tag_regex\\*" doc | sort -u | sed 's/*//g') \
-    <(grep --exclude=tags -roh "|$tag_regex|" doc | sort -u | sed 's/|//g') \
-    | grep '^+[^+]' && exit_code=1
+set -o pipefail
+docker run "${docker_flags[@]}" test/script/check-tag-references || exit_code=$?
+set +o pipefail
 
 echo '========================================'
 echo 'diff supported-tools.md and doc/ale-supported-languages-and-tools.txt tables'
@@ -46,7 +44,9 @@ echo '========================================'
 echo 'Differences follow:'
 echo
 
-test/script/check-supported-tools-tables || exit_code=$?
+set -o pipefail
+docker run "${docker_flags[@]}" test/script/check-supported-tools-tables || exit_code=$?
+set +o pipefail
 
 echo '========================================'
 echo 'Look for badly aligned doc tags'
@@ -54,18 +54,18 @@ echo '========================================'
 echo 'Badly aligned tags follow:'
 echo
 
-# Documentation tags need to be aligned to the right margin, so look for
-# tags which aren't at the right margin.
-grep ' \*[^*]\+\*$' doc/ -r \
-    | awk '{ sep = index($0, ":"); if (length(substr($0, sep + 1 )) < 79) { print } }' \
-    | grep . && exit_code=1
+set -o pipefail
+docker run "${docker_flags[@]}" test/script/check-tag-alignment || exit_code=$?
+set +o pipefail
 
 echo '========================================'
 echo 'Look for table of contents issues'
 echo '========================================'
 echo
 
-test/script/check-toc || exit_code=$?
+set -o pipefail
+docker run "${docker_flags[@]}" test/script/check-toc || exit_code=$?
+set +o pipefail
 
 echo '========================================'
 echo 'Check Python code'
diff --git a/test/script/custom-linting-rules b/test/script/custom-linting-rules
index 981a9459..86294f71 100755
--- a/test/script/custom-linting-rules
+++ b/test/script/custom-linting-rules
@@ -53,17 +53,29 @@ check_errors() {
     regex="$1"
     message="$2"
     include_arg=''
+    exclude_arg=''
 
     if [ $# -gt 2 ]; then
         include_arg="--include $3"
     fi
 
+    if [ $# -gt 3 ]; then
+        shift
+        shift
+        shift
+
+        while (( "$#" )); do
+          exclude_arg="$exclude_arg --exclude $1"
+          shift
+        done
+    fi
+
     for directory in "${directories[@]}"; do
         # shellcheck disable=SC2086
         while read -r; do
             RETURN_CODE=1
             echo "$REPLY $message"
-        done < <(grep -H -n "$regex" $include_arg "$directory"/**/*.vim \
+        done < <(grep -H -n "$regex" $include_arg $exclude_arg "$directory"/**/*.vim \
             | grep -v 'no-custom-checks' \
             | grep -o '^[^:]\+:[0-9]\+' \
             | sed 's:^\./::')
@@ -92,7 +104,7 @@ if (( FIX_ERRORS )); then
     done
 fi
 
-# The arguments are: regex, explanation, [filename_filter]
+# The arguments are: regex, explanation, [filename_filter], [list, of, exclusions]
 check_errors \
     '^function.*) *$' \
     'Function without abort keyword (See :help except-compat)'
@@ -114,7 +126,10 @@ check_errors '==?' "Use 'is?' instead of '==?'. 0 ==? 'foobar' is true"
 check_errors '!=#' "Use 'isnot#' instead of '!=#'. 0 !=# 'foobar' is false"
 check_errors '!=?' "Use 'isnot?' instead of '!=?'. 0 !=? 'foobar' is false"
 check_errors '^ *:\?echo' "Stray echo line. Use \`execute echo\` if you want to echo something"
-check_errors $'name.:.*\'[a-z_]*[^a-z_0-9][a-z_0-9]*\',$' 'Use snake_case names for linters' '*/ale_linters/*'
+# Exclusions for grandfathered-in exceptions
+exclusions="clojure/clj_kondo.vim elixir/elixir_ls.vim go/golangci_lint.vim swift/swiftformat.vim"
+# shellcheck disable=SC2086
+check_errors $'name.:.*\'[a-z_]*[^a-z_0-9][a-z_0-9]*\',$' 'Use snake_case names for linters' '*/ale_linters/*' $exclusions
 # Checks for improving type checks.
 check_errors $'\\(==.\\?\\|is\\) type([\'"]\+)' "Use 'is v:t_string' instead"
 check_errors '\(==.\?\|is\) type([0-9]\+)' "Use 'is v:t_number' instead"