diff --git a/foundryup.sh b/foundryup.sh
new file mode 100644
index 0000000..4045256
--- /dev/null
+++ b/foundryup.sh
@@ -0,0 +1,247 @@
+#!/usr/bin/env bash
+set -e
+# 2022.12.20
+# https://raw.githubusercontent.com/foundry-rs/foundry/master/foundryup/foundryup
+FOUNDRY_DIR=${FOUNDRY_DIR-"$HOME/.foundry"}
+FOUNDRY_BIN_DIR="$FOUNDRY_DIR/bin"
+FOUNDRY_MAN_DIR="$FOUNDRY_DIR/share/man/man1"
+
+main() {
+  need_cmd git
+  need_cmd curl
+
+  while [[ $1 ]]; do
+    case $1 in
+      --)               shift; break;;
+
+      -r|--repo)        shift; FOUNDRYUP_REPO=$1;;
+      -b|--branch)      shift; FOUNDRYUP_BRANCH=$1;;
+      -v|--version)     shift; FOUNDRYUP_VERSION=$1;;
+      -p|--path)        shift; FOUNDRYUP_LOCAL_REPO=$1;;
+      -P|--pr)          shift; FOUNDRYUP_PR=$1;;
+      -C|--commit)      shift; FOUNDRYUP_COMMIT=$1;;
+      -h|--help)
+        usage
+        exit 0
+        ;;
+      *)
+        err "internal error: unknown option "$1"\n";;
+    esac; shift
+  done
+
+  if [ ! -z "$FOUNDRYUP_PR" ]; then
+    if [ -z "$FOUNDRYUP_BRANCH" ]; then
+      FOUNDRYUP_BRANCH="refs/pull/$FOUNDRYUP_PR/head"
+    else
+      err "can't use --pr and --branch at the same time"
+    fi
+  fi
+
+  # Installs foundry from a local repository if --path parameter is provided
+  if [[ -n "$FOUNDRYUP_LOCAL_REPO" ]]; then
+    need_cmd cargo
+
+    # Ignore branches/versions as we do not want to modify local git state
+    if [ -n "$FOUNDRYUP_REPO" ] || [ -n "$FOUNDRYUP_BRANCH" ] || [ -n "$FOUNDRYUP_VERSION" ]; then
+      warn "--branch, --version, and --repo arguments are ignored during local install"
+    fi
+
+    # Enter local repo and build
+    say "installing from $FOUNDRYUP_LOCAL_REPO"
+    cd $FOUNDRYUP_LOCAL_REPO
+    RUSTFLAGS="-C target-cpu=native" ensure cargo build --release # need 4 speed
+
+
+    # Remove prior installations if they exist
+    rm -f "$FOUNDRY_BIN_DIR/forge"
+    rm -f "$FOUNDRY_BIN_DIR/cast"
+    rm -f "$FOUNDRY_BIN_DIR/anvil"
+    rm -f "$FOUNDRY_BIN_DIR/chisel"
+
+    # Symlink from local repo binaries to bin dir
+    ensure ln -s "$PWD/target/release/forge" "$FOUNDRY_BIN_DIR/forge"
+    ensure ln -s "$PWD/target/release/cast" "$FOUNDRY_BIN_DIR/cast"
+    ensure ln -s "$PWD/target/release/anvil" "$FOUNDRY_BIN_DIR/anvil"
+    ensure ln -s "$PWD/target/release/chisel" "$FOUNDRY_BIN_DIR/chisel"
+
+    say "done"
+    exit 0
+  fi
+
+  FOUNDRYUP_REPO=${FOUNDRYUP_REPO-foundry-rs/foundry}
+
+  if [[ "$FOUNDRYUP_REPO" == "foundry-rs/foundry" && -z "$FOUNDRYUP_BRANCH" && -z "$FOUNDRYUP_COMMIT" ]]; then
+    FOUNDRYUP_VERSION=${FOUNDRYUP_VERSION-nightly}
+    FOUNDRYUP_TAG=$FOUNDRYUP_VERSION
+
+    # Normalize versions (handle channels, versions without v prefix
+    if [[ "$FOUNDRYUP_VERSION" == "nightly" ]]; then
+      # Locate real nightly tag
+      SHA=$(ensure curl -sSf https://api.github.com/repos/${FOUNDRYUP_REPO}/git/refs/tags/nightly \
+        | grep -Eo '"sha"[^,]*' \
+        | grep -Eo '[^:]*$' \
+        | tr -d '"' \
+        | tr -d ' ')
+      FOUNDRYUP_TAG="nightly-${SHA}"
+    elif [[ "$FOUNDRYUP_VERSION" == nightly* ]]; then
+      FOUNDRYUP_VERSION="nightly"
+    elif [[ "$FOUNDRYUP_VERSION" == [[:digit:]]* ]]; then
+      # Add v prefix
+      FOUNDRYUP_VERSION="v${FOUNDRYUP_VERSION}"
+      FOUNDRYUP_TAG="${FOUNDRYUP_VERSION}"
+    fi
+
+    say "installing foundry (version ${FOUNDRYUP_VERSION}, tag ${FOUNDRYUP_TAG})"
+
+    PLATFORM="$(uname -s)"
+    case $PLATFORM in
+      Linux)
+        PLATFORM="linux"
+        ;;
+      Darwin)
+        PLATFORM="darwin"
+        ;;
+      *)
+        err "unsupported platform: $PLATFORM"
+        ;;
+    esac
+
+    ARCHITECTURE="$(uname -m)"
+    if [ "${ARCHITECTURE}" = "x86_64" ]; then
+      # Redirect stderr to /dev/null to avoid printing errors if non Rosetta.
+      if [ "$(sysctl -n sysctl.proc_translated 2>/dev/null)" = "1" ]; then
+        ARCHITECTURE="arm64" # Rosetta.
+      else
+        ARCHITECTURE="amd64" # Intel.
+      fi
+    elif [ "${ARCHITECTURE}" = "arm64" ] ||[ "${ARCHITECTURE}" = "aarch64" ] ; then
+      ARCHITECTURE="arm64" # Arm.
+    else
+      ARCHITECTURE="amd64" # Amd.
+    fi
+
+    # Compute the URL of the release tarball in the Foundry repository.
+    RELEASE_URL="https://github.com/${FOUNDRYUP_REPO}/releases/download/${FOUNDRYUP_TAG}/"
+    BIN_TARBALL_URL="${RELEASE_URL}foundry_${FOUNDRYUP_VERSION}_${PLATFORM}_${ARCHITECTURE}.tar.gz"
+    MAN_TARBALL_URL="${RELEASE_URL}foundry_man_${FOUNDRYUP_VERSION}.tar.gz"
+
+    # Download the binaries tarball and unpack it into the .foundry bin directory.
+    say "downloading latest forge, cast, anvil, and chisel"
+    ensure curl -# -L $BIN_TARBALL_URL | tar -xzC $FOUNDRY_BIN_DIR
+    # Download the man tarball and unpack it into the .foundry man directory.
+    say "downloading manpages"
+    ensure curl -# -L $MAN_TARBALL_URL | tar -xzC $FOUNDRY_MAN_DIR
+    say "installed - $($FOUNDRY_BIN_DIR/forge --version)"
+    say "installed - $($FOUNDRY_BIN_DIR/cast --version)"
+    say "installed - $($FOUNDRY_BIN_DIR/anvil --version)"
+    say "installed - $($FOUNDRY_BIN_DIR/chisel --version)"
+    say "done"
+
+    if [[ $(which forge) =~ "cargo" ]]; then
+      warn "it appears your system has already has forge installed via cargo. you may need to run 'rm $(which forge)' to allow foundryup to take precedence!"
+    fi
+
+    if [[ $(which cast) =~ "cargo" ]]; then
+      warn "it appears your system has already has cast installed via cargo. you may need to run 'rm $(which cast)' to allow foundryup to take precedence!"
+    fi
+
+    if [[ $(which anvil) =~ "cargo" ]]; then
+      warn "it appears your system has already has anvil installed via cargo. you may need to run 'rm $(which anvil)' to allow foundryup to take precedence!"
+    fi
+
+    if [[ $(which chisel) =~ "cargo" ]]; then
+      warn "it appears your system has already has chisel installed via cargo. you may need to run 'rm $(which chisel)' to allow foundryup to take precedence!"
+    fi
+  else
+    need_cmd cargo
+    FOUNDRYUP_BRANCH=${FOUNDRYUP_BRANCH-master}
+    REPO_PATH="${FOUNDRY_DIR}/${FOUNDRYUP_REPO}"
+
+    if [ ! -d $REPO_PATH ]; then
+      # Repo path did not exist, grab the author from the repo, make a directory in .foundry, cd to it and clone.
+      IFS="/" read -ra AUTHOR <<< "$FOUNDRYUP_REPO"
+      ensure mkdir -p "$FOUNDRY_DIR/$AUTHOR"
+      cd "$FOUNDRY_DIR/$AUTHOR"
+      ensure git clone https://github.com/${FOUNDRYUP_REPO}
+    fi
+    # force checkout, discarding any local changes
+    cd $REPO_PATH
+    ensure git fetch origin ${FOUNDRYUP_BRANCH}:remotes/origin/${FOUNDRYUP_BRANCH}
+    ensure git checkout origin/${FOUNDRYUP_BRANCH}
+    # checkout submodules for Chisel build
+    ensure git submodule update --init --recursive
+    # If set, checkout specific commit from branch
+    if [ ! -z $FOUNDRYUP_COMMIT ]; then
+      say "installing at commit ${FOUNDRYUP_COMMIT}"
+      ensure git checkout ${FOUNDRYUP_COMMIT}
+    fi
+    # Build the repo and install it locally to the .foundry bin directory.
+    # --root appends /bin to the directory it is given, so we pass FOUNDRY_DIR.
+    RUSTFLAGS="-C target-cpu=native" ensure cargo install --path ./cli --bins --locked --force --root $FOUNDRY_DIR
+    # install anvil
+    RUSTFLAGS="-C target-cpu=native" ensure cargo install --path ./anvil --bin anvil --locked --force --root $FOUNDRY_DIR
+    # install chisel
+    RUSTFLAGS="-C target-cpu=native" ensure cargo install --path ./chisel --bin chisel --locked --force --root $FOUNDRY_DIR
+
+    # If help2man is installed, use it to add Foundry man pages.
+    if command -v help2man &> /dev/null ; then
+      help2man -N $FOUNDRY_BIN_DIR/forge > $FOUNDRY_MAN_DIR/forge.1
+      help2man -N $FOUNDRY_BIN_DIR/cast > $FOUNDRY_MAN_DIR/cast.1
+      help2man -N $FOUNDRY_BIN_DIR/anvil > $FOUNDRY_MAN_DIR/anvil.1
+      help2man -N $FOUNDRY_BIN_DIR/chisel > $FOUNDRY_MAN_DIR/chisel.1
+    fi
+    say "done"
+  fi
+}
+
+usage() {
+  cat 1>&2 <<EOF
+The installer for Foundry.
+
+Update or revert to a specific Foundry version with ease.
+
+USAGE:
+    foundryup <OPTIONS>
+
+OPTIONS:
+    -h, --help      Print help information
+    -v, --version   Install a specific version
+    -b, --branch    Install a specific branch
+    -P, --pr        Install a specific Pull Request
+    -C, --commit    Install a specific commit
+    -r, --repo      Install from a remote GitHub repo (uses default branch if no other options are set)
+    -p, --path      Install a local repository
+EOF
+}
+
+say() {
+  printf 'foundryup: %s\n' "$1"
+}
+
+warn() {
+  say "warning: ${1}" >&2
+}
+
+err() {
+  say "$1" >&2
+  exit 1
+}
+
+need_cmd() {
+  if ! check_cmd "$1"; then
+    err "need '$1' (command not found)"
+  fi
+}
+
+check_cmd() {
+  command -v "$1" > /dev/null 2>&1
+}
+
+# Run a command that should never fail. If the command fails execution
+# will immediately terminate with an error showing the failing
+# command.
+ensure() {
+  if ! "$@"; then err "command failed: $*"; fi
+}
+
+main "$@" || exit 1
diff --git a/install b/install
index 1c7d730..72f4c90 100755
--- a/install
+++ b/install
@@ -1,196 +1,56 @@
 #!/usr/bin/env bash
 set -e
 
-echo "Installing foundryup..."
+echo Installing foundryup...
 
 FOUNDRY_DIR=${FOUNDRY_DIR-"$HOME/.foundry"}
 FOUNDRY_BIN_DIR="$FOUNDRY_DIR/bin"
 FOUNDRY_MAN_DIR="$FOUNDRY_DIR/share/man/man1"
 
-# runs with Makefile to generate hash on CI
-# shellcheck disable=SC2034
-SCRIPT_COMMIT_SHA="${LOAD_SCRIPT_COMMIT_SHA}"
-
-PLATFORM="$(uname -s)"
-  case $PLATFORM in
-    Linux)
-      PLATFORM="linux"
-      ;;
-    Darwin)
-      PLATFORM="darwin"
-      ;;
-    *)
-      echo "foundryup: unsupported platform: $PLATFORM"
-      exit 1
-      ;;
-esac
-
-# shellcheck disable=SC2016
-FOUNDRYUP='#!/usr/bin/env bash
-set -e
-
-
-FOUNDRY_DIR=${FOUNDRY_DIR-"$HOME/.foundry"}
-FOUNDRY_BIN_DIR="$FOUNDRY_DIR/bin"
-FOUNDRY_MAN_DIR="$FOUNDRY_DIR/share/man/man1"
-while [[ $1 ]]; do
-  case $1 in
-    --)               shift; break;;
-    -r|--repo)        shift; FOUNDRYUP_REPO=$1;;
-    -b|--branch)      shift; FOUNDRYUP_BRANCH=$1;;
-    -v|--version)     shift; FOUNDRYUP_VERSION=$1;;
-    -h|--help)        FOUNDRYUP_HELP="1";;
-    *) printf "foundryup: internal error: %q\\n" "$1"; exit 1
-  esac; shift
-done
-if [[ "$FOUNDRYUP_HELP" == "1" ]]; then
-    echo "Update or revert to a specific Foundry branch with ease.
-USAGE:
-    foundryup <OPTIONS>
-OPTIONS:
-    -h, --help      Print help information
-    -v, --version   Install a specific version
-    -b, --branch    Install a specific branch
-    -r, --repo      Install a forks main branch"
-    exit 0
-fi
-FOUNDRYUP_REPO=${FOUNDRYUP_REPO-gakonst/foundry}
-if [[ "$FOUNDRYUP_REPO" == "gakonst/foundry" && -z "$FOUNDRYUP_BRANCH" ]]; then
-  FOUNDRYUP_VERSION=${FOUNDRYUP_VERSION-nightly}
-  FOUNDRYUP_TAG=$FOUNDRYUP_VERSION
-  # Normalize versions (handle channels, versions without v prefix
-  if [[ "$FOUNDRYUP_VERSION" == "nightly" ]]; then
-    # Locate real nightly tag
-    SHA=$(curl -sSf https://api.github.com/repos/${FOUNDRYUP_REPO}/git/refs/tags/nightly \
-      | grep -Eo '\''"sha"[^,]*'\'' \
-      | grep -Eo '\''[^:]*$'\'' \
-      | tr -d '\''"'\'' \
-      | tr -d '\'' '\'')
-    FOUNDRYUP_TAG="nightly-${SHA}"
-  elif [[ "$FOUNDRYUP_VERSION" == [[:digit:]]* ]]; then
-    # Add v prefix
-    FOUNDRYUP_VERSION="v${FOUNDRYUP_VERSION}"
-    FOUNDRYUP_TAG="${FOUNDRYUP_VERSION}"
-  fi
-  PLATFORM="$(uname -s)"
-  case $PLATFORM in
-    Linux)
-      PLATFORM="linux"
-      ;;
-    Darwin)
-      PLATFORM="darwin"
-      ;;
-    *)
-      echo "foundryup: unsupported platform: $PLATFORM"
-      exit 1
-      ;;
-  esac
-  ARCHITECTURE="$(uname -m)"
-  if [ "${ARCHITECTURE}" = "x86_64" ]; then
-    # Redirect stderr to /dev/null to avoid printing errors if non Rosetta.
-    if [ "$(sysctl -n sysctl.proc_translated 2>/dev/null)" = "1" ]; then
-      ARCHITECTURE="arm64" # Rosetta.
-    else
-      ARCHITECTURE="amd64" # Intel.
-    fi
-  elif [ "${ARCHITECTURE}" = "arm64" ] ||[ "${ARCHITECTURE}" = "aarch64" ] ; then
-    ARCHITECTURE="arm64" # Arm.
-  else
-    ARCHITECTURE="amd64" # Amd.
-  fi
-  # Compute the URL of the release tarball in the Foundry repository.
-  RELEASE_URL="https://github.com/${FOUNDRYUP_REPO}/releases/download/${FOUNDRYUP_TAG}/"
-  BIN_TARBALL_URL="${RELEASE_URL}foundry_${FOUNDRYUP_VERSION}_${PLATFORM}_${ARCHITECTURE}.tar.gz"
-  MAN_TARBALL_URL="${RELEASE_URL}foundry_man_${FOUNDRYUP_VERSION}.tar.gz"
-  # Download the binaries tarball and unpack it into the .foundry bin directory.
-  curl -L $BIN_TARBALL_URL | tar -xvzC $FOUNDRY_BIN_DIR
-  # Download the man tarball and unpack it into the .foundry man directory.
-  curl -L $MAN_TARBALL_URL | tar -xvzC $FOUNDRY_MAN_DIR
-  echo foundryup: done!
-else
-  FOUNDRYUP_BRANCH=${FOUNDRYUP_BRANCH-master}
-  if ! command -v cargo &> /dev/null ; then
-    # Error if cargo is not already installed.
-    echo "foundryup: cargo is not installed. Please install it first."
-    exit 1
-  fi
-  REPO_PATH="${FOUNDRY_DIR}/${FOUNDRYUP_REPO}"
-  if [ -d $REPO_PATH ]; then
-    # If the repo path exists move to it and do a force checkout, discarding any local changes
-    cd $REPO_PATH
-    git fetch
-    git reset --hard origin/${FOUNDRYUP_BRANCH}
-  else
-    # Repo path did not exist, grab the author from the repo, make a directory in .foundry, cd to it and clone.
-    IFS="/" read -ra AUTHOR <<< "$FOUNDRYUP_REPO"
-    mkdir -p "$FOUNDRY_DIR/$AUTHOR"
-    cd "$FOUNDRY_DIR/$AUTHOR"
-    git clone https://github.com/${FOUNDRYUP_REPO}
-    cd $REPO_PATH
-    git checkout ${FOUNDRYUP_BRANCH}
-  fi
-  # Build the repo and install it locally to the .foundry bin directory.
-  # --root appends /bin to the directory it is given, so we pass FOUNDRY_DIR.
-  cargo install --path ./cli --bins --locked --force --root $FOUNDRY_DIR
-  # If help2man is installed, use it to add Foundry man pages.
-  if command -v help2man &> /dev/null ; then
-    help2man -N $FOUNDRY_BIN_DIR/forge > $FOUNDRY_MAN_DIR/forge.1
-    help2man -N $FOUNDRY_BIN_DIR/cast > $FOUNDRY_MAN_DIR/cast.1
-  fi
-  echo "foundryup: done!"
-fi'
-
-BINARY="$FOUNDRY_BIN_DIR/foundryup"
+BIN_URL="https://raw.githubusercontent.com/foundry-rs/foundry/master/foundryup/foundryup"
+BIN_PATH="$FOUNDRY_BIN_DIR/foundryup"
 
 # Create the .foundry bin directory and foundryup binary if it doesn't exist.
-mkdir -p "$FOUNDRY_BIN_DIR"
-echo "$FOUNDRYUP" >"$BINARY"
-chmod +x "$BINARY"
+mkdir -p $FOUNDRY_BIN_DIR
+curl -# -L $BIN_URL -o $BIN_PATH
+chmod +x $BIN_PATH
 
 # Create the man directory for future man files if it doesn't exist.
-mkdir -p "$FOUNDRY_MAN_DIR"
+mkdir -p $FOUNDRY_MAN_DIR
 
 # Store the correct profile file (i.e. .profile for bash or .zshrc for ZSH).
 case $SHELL in
 */zsh)
-	PROFILE=$HOME/.zshrc
-	PREF_SHELL=zsh
-	;;
+    PROFILE=$HOME/.zshrc
+    PREF_SHELL=zsh
+    ;;
 */bash)
-	PROFILE=$HOME/.bashrc
-	PREF_SHELL=bash
-	;;
+    PROFILE=$HOME/.bashrc
+    PREF_SHELL=bash
+    ;;
 */fish)
-	PROFILE=$HOME/.config/fish/config.fish
-	PREF_SHELL=fish
-	;;
+    PROFILE=$HOME/.config/fish/config.fish
+    PREF_SHELL=fish
+    ;;
+*/ash)
+    PROFILE=$HOME/.profile
+    PREF_SHELL=ash
+    ;;
 *)
-	echo "foundryup: could not detect shell, manually add ${FOUNDRY_BIN_DIR} to your PATH."
-	exit 1
-	;;
-
+    echo "foundryup: could not detect shell, manually add ${FOUNDRY_BIN_DIR} to your PATH."
+    exit 1
 esac
 
 # Only add foundryup if it isn't already in PATH.
 if [[ ":$PATH:" != *":${FOUNDRY_BIN_DIR}:"* ]]; then
-	if [[ $PLATFORM == 'darwin'* ]]; then
-		echo >>"$HOME"/.bash_profile && echo "export PATH=\"\$PATH:$FOUNDRY_BIN_DIR\"" >>"$HOME"/.bash_profile
-	fi
-	# Add the foundryup directory to the path and ensure the old PATH variables remain.
-	echo >>"$PROFILE" && echo "export PATH=\"\$PATH:$FOUNDRY_BIN_DIR\"" >>"$PROFILE"
+    # Add the foundryup directory to the path and ensure the old PATH variables remain.
+    echo >> $PROFILE && echo "export PATH=\"\$PATH:$FOUNDRY_BIN_DIR\"" >> $PROFILE
 fi
 
-
-if [[ $SHELL == 'bash'* ]]; then
-forge completions bash > /usr/local/etc/bash_completion.d/forge
-cast completions bash > /usr/local/etc/bash_completion.d/cast
-
-echo >> "/usr/local/etc/bash_completion.d/forge">>$$HOME/.bash_profile
-echo >> "source /usr/local/etc/bash_completion.d/cast">>$$HOME/.bash_profile
-# echo >>"[ -f /usr/local/etc/bash_completion.d ] && . /usr/local/etc/bash_completion.d ">>$$HOME/.bash_profile
+# Warn MacOS users that they may need to manually install libusb via Homebrew:
+if [[ "$OSTYPE" =~ ^darwin && ! -f /usr/local/opt/libusb/lib/libusb-1.0.0.dylib ]]; then
+    echo && echo "warning: libusb not found. You may need to install it manually on MacOS via Homebrew (brew install libusb)."
 fi
 
 echo && echo "Detected your preferred shell is ${PREF_SHELL} and added foundryup to PATH. Run 'source ${PROFILE}' or start a new terminal session to use foundryup."
 echo "Then, simply run 'foundryup' to install Foundry."
-sleep 1
-exit 0
diff --git a/src/install b/src/install
new file mode 100644
index 0000000..261bdf7
--- /dev/null
+++ b/src/install
@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+set -e
+
+echo Installing foundryup...
+
+FOUNDRY_DIR=${FOUNDRY_DIR-"$HOME/.foundry"}
+FOUNDRY_BIN_DIR="$FOUNDRY_DIR/bin"
+FOUNDRY_MAN_DIR="$FOUNDRY_DIR/share/man/man1"
+
+BIN_URL="https://raw.githubusercontent.com/foundry-rs/foundry/master/foundryup/foundryup"
+BIN_PATH="$FOUNDRY_BIN_DIR/foundryup"
+
+# Create the .foundry bin directory and foundryup binary if it doesn't exist.
+mkdir -p $FOUNDRY_BIN_DIR
+curl -# -L $BIN_URL -o $BIN_PATH
+chmod +x $BIN_PATH
+
+# Create the man directory for future man files if it doesn't exist.
+mkdir -p $FOUNDRY_MAN_DIR
+
+# Store the correct profile file (i.e. .profile for bash or .zshrc for ZSH).
+case $SHELL in
+*/zsh)
+    PROFILE=$HOME/.zshrc
+    PREF_SHELL=zsh
+    ;;
+*/bash)
+    PROFILE=$HOME/.bashrc
+    PREF_SHELL=bash
+    ;;
+*/fish)
+    PROFILE=$HOME/.config/fish/config.fish
+    PREF_SHELL=fish
+    ;;
+*)
+    echo "foundryup: could not detect shell, manually add ${FOUNDRY_BIN_DIR} to your PATH."
+    exit 1
+esac
+
+# Only add foundryup if it isn't already in PATH.
+if [[ ":$PATH:" != *":${FOUNDRY_BIN_DIR}:"* ]]; then
+    # Add the foundryup directory to the path and ensure the old PATH variables remain.
+    echo >> $PROFILE && echo "export PATH=\"\$PATH:$FOUNDRY_BIN_DIR\"" >> $PROFILE
+fi
+
+# Warn MacOS users that they may need to manually install libusb via Homebrew:
+if [[ "$OSTYPE" =~ ^darwin && ! -f /usr/local/opt/libusb/lib/libusb-1.0.0.dylib ]]; then
+    echo && echo "warning: libusb not found. You may need to install it manually on MacOS via Homebrew (brew install libusb)."
+fi
+
+echo && echo "Detected your preferred shell is ${PREF_SHELL} and added foundryup to PATH. Run 'source ${PROFILE}' or start a new terminal session to use foundryup."
+echo "Then, simply run 'foundryup' to install Foundry."