そんな日もあります。
$ brew install helm@2
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 3 taps (homebrew/core, homebrew/cask and aws/tap).
==> Updated Formulae
Updated 110 formulae.
==> New Casks
box-tools cloudflare-warp marathon-infinity marathon2
==> Updated Casks
1password-cli eloston-chromium mathpix-snipping-tool sequel-ace
4k-stogram eve-launcher matterhorn shift
abstract final-cut-library-manager microsoft-azure-storage-explorer signal
activedock freeplane mongodb-compass sipgate-softphone
appcode grids mongodb-compass-isolated-edition skype
audirvana http-toolkit mongodb-compass-readonly slack
aws-vault ibored odrive slite
axure-rp icollections openphone snes9x
backblaze icq opera streamlabs-obs
baidunetdisk intune-company-portal pagico supercollider
blender jami permute telavox-flow
bootstrap-studio joplin pixelsnap tiger-trade
bria keep-it plex ubersicht
cacher keysmith portfolioperformance upwork
camo-studio kodelife privatevpn vmware-horizon-client
chef-workstation launchbar proclaim watchguard-mobile-vpn-with-ssl
chirp libreoffice qcad webots
cryo libreoffice-language-pack quickhash whalebird
dcp-o-matic-batch-converter loaf quip workflowy
downie logos refined-github-safari
dynobase mailmate remember-the-milk
element marginnote sensei
==> Deleted Casks
box-edit phiewer
==> Downloading https://homebrew.bintray.com/bottles/helm%402-2.16.10.catalina.bottle.tar.gz
==> Downloading from https://d29vzk4ow07wi7.cloudfront.net/c29eda468036c44de62924d971cbe13bb3073ac0306dce23dd1089173ce127c5?response-conten
######################################################################## 100.0%
==> Pouring helm@2-2.16.10.catalina.bottle.tar.gz
==> Caveats
helm@2 is keg-only, which means it was not symlinked into /usr/local,
because this is an alternate version of another formula.
If you need to have helm@2 first in your PATH run:
echo 'export PATH="/usr/local/opt/helm@2/bin:$PATH"' >> ~/.zshrc
Bash completion has been installed to:
/usr/local/opt/helm@2/etc/bash_completion.d
zsh completions have been installed to:
/usr/local/opt/helm@2/share/zsh/site-functions
==> Summary
🍺 /usr/local/Cellar/helm@2/2.16.10: 51 files, 87.5MB
$ ls /uls /usr/local/Cellar/helm@2/2.16.10/bin
helm tiller
$ alias helm2=/usr/local/Cellar/helm@2/2.16.10/bin/helm
$ helm2 version
Client: &version.Version{SemVer:"v2.16.10", GitCommit:"bceca24a91639f045f22ab0f41e47589a932cf5e", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.16.8", GitCommit:"145206680c1d5c28e3fcf30d6f596f0ba84fcb47", GitTreeState:"clean"}
$ helm version
version.BuildInfo{Version:"v3.1.1", GitCommit:"afe70585407b420d0097d07b21c47dc511525ac8", GitTreeState:"clean", GoVersion:"go1.13.8"}
特定バージョン
$ curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/master/scripts/get
$ chmod 700 get_helm.sh
$ ./get_helm.sh -v v2.13.0