Replace in-sudo with env

`(env)[22c8c23f40/src/env.c (L53)]` seems to supports equal strings since before 2016.

scripts/binary-tarball.nix

@@ -23,7 +23,6 @@ in
 runCommand "nix-binary-tarball-${version}" env ''
   cp ${installerClosureInfo}/registration $TMPDIR/reginfo
   cp ${./create-darwin-volume.sh} $TMPDIR/create-darwin-volume.sh
-  cp ${./in-sudo.sh} $TMPDIR/in-sudo
   substitute ${./install-nix-from-closure.sh} $TMPDIR/install \
     --subst-var-by nix ${nix} \
     --subst-var-by cacert ${cacert}
@@ -45,7 +44,6 @@ runCommand "nix-binary-tarball-${version}" env ''
     shellcheck $TMPDIR/create-darwin-volume.sh
     shellcheck $TMPDIR/install-darwin-multi-user.sh
     shellcheck $TMPDIR/install-systemd-multi-user.sh
-    shellcheck $TMPDIR/in-sudo
 
     # SC1091: Don't panic about not being able to source
     #         /etc/profile
@@ -63,7 +61,6 @@ runCommand "nix-binary-tarball-${version}" env ''
   chmod +x $TMPDIR/install-darwin-multi-user.sh
   chmod +x $TMPDIR/install-systemd-multi-user.sh
   chmod +x $TMPDIR/install-multi-user
-  chmod +x $TMPDIR/in-sudo
   dir=nix-${version}-${system}
   fn=$out/$dir.tar.xz
   mkdir -p $out/nix-support
@@ -82,7 +79,6 @@ runCommand "nix-binary-tarball-${version}" env ''
     $TMPDIR/install-darwin-multi-user.sh \
     $TMPDIR/install-systemd-multi-user.sh \
     $TMPDIR/install-multi-user \
-    $TMPDIR/in-sudo \
     $TMPDIR/reginfo \
     $(cat ${installerClosureInfo}/store-paths)
 ''

scripts/in-sudo.sh

@@ -1,19 +0,0 @@
-#!/usr/bin/env bash
-
-export_equal_string() {
-    local equal_string=$1
-
-    local variable_name value
-    IFS='=' read -r -d $'\0' variable_name value <<< "$equal_string"
-    value=${value:0:-1}
-    eval "export $variable_name=$(printf '%q' "$value")"
-}
-
-while [ $# -gt 0 ]; do
-    case "$1" in
-        *=*) export_equal_string "$1"; shift ;;
-        *) break ;;
-    esac
-done
-
-"$@"

scripts/install-multi-user.sh

@@ -58,7 +58,6 @@ readonly EXTRACTED_NIX_PATH="$(dirname "$0")"
 
 readonly ROOT_HOME=~root
 
-readonly IN_SUDO=$EXTRACTED_NIX_PATH/in-sudo
 readonly PROXY_ENVIRONMENT_VARIABLES=(
     http_proxy
     https_proxy
@@ -387,7 +386,7 @@ _sudo() {
     if is_root; then
         env "$@"
     else
-        sudo "$IN_SUDO" "${SUDO_EXTRA_ENVIRONMENT_VARIABLES[@]}" "$@"
+        sudo env "${SUDO_EXTRA_ENVIRONMENT_VARIABLES[@]}" "$@"
     fi
 }