Have a project that requires multiple versions of terraform? what? you don't want to...

clone the terraform source repo

  ~  git remote -v
  origin  https://github.com/hashicorp/terraform.git (fetch)
  origin  https://github.com/hashicorp/terraform.git (push)

check out the tag you want

  ~  git tag | tail -1
  v1.1.5
  ~  git checkout v1.1.5
  Previous HEAD position was 516295951 Release v1.1.4
  HEAD is now at fe2ddc22a Release v1.1.5

compile/install the binary in a local bin dirctory,

  ~  go build
  go: downloading github.com/aws/aws-sdk-go v1.42.35
  ~  install terraform ~/bin/terraform-v1.1.5
  ~  ls ~/bin/terraform\*
  /home/matt/bin/terraform          /home/matt/bin/terraform-v0.13.7  /home/matt/bin/terraform-v1.1.4
  /home/matt/bin/terraform-v0.13.4  /home/matt/bin/terraform-v0.14.9  /home/matt/bin/terraform-v1.1.5

then manage a series of brittle aliases to disptach the proper version?

  ~  which terraform
  terraform () {
    binary=terraform
    if [[ $1 == "v"\* ]] && [[ $1 != "validate" ]]
    then
      version=$1
      shift
      binary="$binary-$version"
      [ -f ~/bin/$binary ] || bail 1 "missing binary $binary" || return 1
    else
      binary=/usr/bin/$binary
    fi
    dispatch --name terraform --scope --slice compilers.slice -c 35 -mh 2048M -mm 2048M -s 1M --binary $binary
  "$@"
  }

(dispatch just runs things with memory and cpu limits)

  ~  which dispatch
  dispatch () {
    if [[ $USER == "root" ]]
    then
      command "$binary" "$@"
      return $?
    fi
    declare args=(--user --same-dir -p IOAccounting=yes -p MemoryAccounting=yes -p TasksAccounting=yes)
    while (($#))
    do
      case "$1" in
        (-c) args+="-p"
          args+="CPUWeight=$2"
          shift 2 ;;
        (-mm) args+="-p"
          args+="MemoryMax=$2"
          shift 2 ;;
        (-mh) args+="-p"
          args+="MemoryHigh=$2"
          shift 2 ;;
        (-s) args+="-p"
          args+="MemorySwapMax=$2"
          shift 2 ;;
        (--scope) args+=--scope
          shift ;;
        (--slice) args+="--slice=$2"
          shift 2 ;;
        (--name) name=$1
          shift 2 ;;
        (-P) args+=-P
          shift ;;
        (--binary) [ -z "$name" ] || name=$2
          binary="$2"
          shift ;;
        (*) break ;;
      esac
    done
    systemd-run $args "$@" 2> >(>&2 grep -vE 'Running.*as unit:')
  }

and of course, then you'd need a shitty little script to call your alias when other tools decide they want to call terraform

  ~  cat ~/bin/terraform
  #!/usr/bin/env zsh
  source ~/.zshrc >/dev/null 2>/dev/null || exit 1
  terraform $@

Because that would be silly and dumb, and I totally don't do that for everything.

Don't even get me started on virtualenvs.