If you are running a Laravel project like Eventmie on XAMPP (LAMPP) in Ubuntu 24 and suddenly see this error:

Webp format is not supported by PHP installation.

You are not alone.

This issue happens frequently when:

• GD extension is enabled
• But WebP support inside GD is not compiled
• Or you are mixing system PHP and XAMPP PHP
• Or Ubuntu version mismatch causes confusion
• Or iconv compilation fails during rebuild

In this guide, I will explain everything in simple and practical terms:

• Why this happens
• How to check which PHP is actually running
• Why GD shows enabled but WebP is missing
• Why installing php8.3-gd does not fix XAMPP
• How to compile PHP with WebP support properly
• Why iconv throws “does not support errno”
• How to safely undo everything
• When to stop server-level fixing and move to code-level solution

This tutorial is based on a real production debugging scenario.

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1. Understanding the Root Problem

The core error:

Webp format is not supported by PHP installation.

This comes from Intervention Image library (used by Eventmie).

Internally it tries:

$image->encode('webp', 90);

If your PHP GD does not support WebP, it throws:

Intervention\Image\Exception\NotSupportedException

Now the most confusing part:

You check GD and it says enabled.

But WebP Support is blank.

Example:

/opt/lampp/bin/php -r 'print_r(gd_info());'

Output:

[GD Version] => bundled (2.1.0 compatible)
[WebP Support] =>

Blank means:
WebP was NOT compiled inside GD.

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2. First Important Question: Which PHP Is Actually Running?

This is critical.

Run:

which php
type -a php
php -v

If you see:

/opt/lampp/bin/php

Then you are using XAMPP PHP.

If you see:

/usr/bin/php

Then you are using system PHP.

Installing:

sudo apt install php8.3-gd

will NOT affect XAMPP PHP.

Because XAMPP is completely independent.

This is one of the biggest misconceptions.

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3. Why Installing php8.3-gd Did Not Fix the Problem

You installed:

sudo apt install php8.3-gd

But your PHP version was:

PHP 8.2.12 (cli)

And it was coming from:

/opt/lampp/bin/php

That means:

System PHP 8.3 ≠ XAMPP PHP 8.2

So installing system packages does nothing for LAMPP.

This is where many developers get stuck.

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4. How to Check If GD WebP Is Really Enabled

Run these three commands:

/opt/lampp/bin/php -m | grep -i gd

/opt/lampp/bin/php -r 'print_r(gd_info());'

/opt/lampp/bin/php -r 'var_dump(function_exists("imagewebp"));'

If you get:

bool(false)

Then WebP support is not compiled.

Even if configure command shows:

--with-webp

That does NOT guarantee WebP actually compiled successfully.

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5. Why Ubuntu 24 Is Not the Real Problem

You asked:

Is Ubuntu 24 creating problem?

Answer:
No.

Ubuntu 24 supports PHP 8.3 officially.

But you are using:

XAMPP PHP 8.2

XAMPP bundles its own PHP binary and libraries.

Ubuntu version is irrelevant unless:

• Required development libraries are missing
• Or you are compiling PHP manually

So Ubuntu is not the root cause.

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6. Can We Recompile XAMPP PHP With GD WebP?

Yes.

But it is advanced and risky.

You attempted:

• Download PHP 8.2.12 source
• Configure with –with-webp
• Build
• Install

And initially WebP was still false.

Later, after proper configuration, you got:

bool(true)
[WebP Support] => 1

That means compilation succeeded.

But then iconv error appeared.

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7. The iconv Error: “iconv does not support errno”

During configure, you saw:

checking if iconv supports errno... no
configure: error: iconv does not support errno

This happens because:

• glibc iconv behaves differently
• PHP configure expects certain behavior
• Ubuntu 24 environment sometimes fails that test

Solutions usually involve:

• Forcing cache variable
• Installing GNU libiconv manually
• Exporting CPPFLAGS and LDFLAGS

But this increases complexity significantly.

For production XAMPP server, recompiling PHP inside LAMPP is not beginner-friendly.

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8. The Biggest Mistake Developers Make

Trying to “fix server” when application-level fallback is easier.

In your case:

Imagick was already working.

Test confirmed:

$im=new Imagick();
$im->setImageFormat("webp");

It successfully created WebP file.

But Eventmie was using GD driver, not Imagick.

So the real fix could be:

Change Intervention driver to Imagick.

Instead of rebuilding entire PHP stack.

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9. Safe Undo – How to Revert Everything

If things get messy:

Delete test install:

sudo rm -rf /opt/lampp-webp-test

Delete source builds:

sudo rm -rf /usr/local/src/php-8.2.12

Clear environment variables:

unset PKG_CONFIG_PATH CPPFLAGS LDFLAGS LD_LIBRARY_PATH
hash -r

Restart XAMPP:

sudo /opt/lampp/lampp restart

Now you are back to original state.

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10. The Smart Production Approach (Recommended)

Instead of rebuilding PHP:

Use one of these:

Option 1: Force Imagick Driver

In config/image.php:

'driver' => 'imagick',

Option 2: Fallback Logic

Wrap WebP encoding:

if (function_exists('imagewebp')) {
    $image->encode('webp', 90);
} else {
    $image->encode('jpg', 90);
}

This avoids server-level risk.

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11. Final Decision Guide

If you are:

Beginner → Do NOT recompile PHP
Production server → Avoid manual rebuild
Using XAMPP → Never mix system PHP packages
Already have Imagick → Use Imagick driver
Need WebP strictly via GD → Compile carefully in isolated environment