diff --git a/README.md b/README.md
index 8f3fe92..070a85f 100644
--- a/README.md
+++ b/README.md
@@ -385,6 +385,7 @@ Here's the list of all the supported environment variables:
| Extension | Environment variable | Description |
|---|---|---|
+| | `IPE_DEBUG=1` | By setting this environment variable, the script will print all the commands it executes (it will be very verbose, useful only for debug purposes) |
| | `IPE_DONT_ENABLE=1` | By default the script will install and enable the extensions.
If you want to only install them (without enabling them) you can set this environment variable.
To enable the extensions at a later time you can execute the command `docker-php-ext-enable-` (for example: `docker-php-ext-enable-xdebug`).
**Beware**: installing some PHP extensions require that other PHP extensions are already enabled, so use this feature wisely. |
| | `IPE_KEEP_SYSPKG_CACHE=1` | By default the script will clear the apt/apk/pear cache in order to save disk space. You can disable it by setting this environment variable |
| lzf | `IPE_LZF_BETTERCOMPRESSION=1` | By default `install-php-extensions` compiles the `lzf` extension to prefer speed over size; you can use this environment variable to compile it preferring size over speed |
diff --git a/install-php-extensions b/install-php-extensions
index f252c97..d7922a1 100755
--- a/install-php-extensions
+++ b/install-php-extensions
@@ -12,6 +12,10 @@
set -o errexit
set -o nounset
+if test "${IPE_DEBUG:-}" = "1"; then
+ set -x
+fi
+
if ! which docker-php-ext-configure >/dev/null || ! which docker-php-ext-enable >/dev/null || ! which docker-php-ext-install >/dev/null || ! which docker-php-source >/dev/null; then
printf 'The script %s is meant to be used with official Docker PHP Images - https://hub.docker.com/_/php\n' "$0" >&2
exit 1