Trying to upgrade a forum running beta 0.1 to stable 1.0 release. I follow the instructions here:
https://docs.flarum.org/update/

But composer kept telling me that we're running PHP 7.2 but I double-checked we're running 7.4 version

- flarum/core[v1.0.0, ..., v1.5.0] require php >=7.3 -> your php version (7.                                                                                                                               > 2.24) does not satisfy that requirement.
Root composer.json requires flarum/core ¹.0 -> satisfiable by flarum/core > [v1.0.0, ..., v1.5.0].

I double checked in Plesk and this domain is running PHP 7.4. I even added a phpinfo() file to the same folder as Flarum and it says PHP Version 7.4.32

So I tried to force the composer update with --ignore-platform-reqs

[root@server forum.somedomain.net]# composer update --prefer-dist --no-plugins --no-dev -a --with-all-dependencies --ignore-platform-reqs
Loading composer repositories with package information
Updating dependencies
Lock file operations: 21 installs, 85 updates, 13 removals

Removing axy/codecs-base64vlq (1.0.1)

Removing axy/errors (1.0.5)

Removing axy/sourcemap (0.1.5)

Removing flarum/auth-facebook (v0.1.0-beta.13)

Removing flarum/auth-github (v0.1.0-beta.13)

Removing flarum/auth-twitter (v0.1.0-beta.13)

Removing league/oauth1-client (v1.10.1)

Removing league/oauth2-client (2.6.1)

Removing league/oauth2-facebook (2.0.5)

Removing league/oauth2-github (2.0.0)

Removing paragonie/random_compat (v9.99.100)

Removing symfony/debug (v4.4.41)

Removing tobscure/json-api (v0.3.0)

Upgrading axy/backtrace (1.0.7 => 2.0.0)

Locking brick/math (0.10.2)

Locking dflydev/dot-access-data (v3.0.1)

Upgrading dflydev/fig-cookies (v2.0.3 => v3.0.0)

Upgrading doctrine/event-manager (1.1.1 => 1.2.0)

Upgrading doctrine/inflector (2.0.4 => 2.0.6)

Locking dragonmantank/cron-expression (v3.3.2)

Upgrading flarum/approval (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/bbcode (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/core (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/emoji (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/flags (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/lang-english (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/likes (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/lock (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/markdown (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/mentions (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/pusher (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/statistics (v0.1.0-beta.15 => v1.5.1)

Upgrading flarum/sticky (v0.1.0-beta.15.1 => v1.5.0)

Upgrading flarum/subscriptions (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/suspend (v0.1.0-beta.15 => v1.5.0)

Upgrading flarum/tags (v0.1.0-beta.15 => v1.5.0)

Upgrading fof/spamblock (0.4.0 => 1.0.2)

Upgrading franzl/whoops-middleware (0.4.1 => 2.0.0)

Upgrading guzzlehttp/guzzle (7.4.3 => 7.5.0)

Upgrading guzzlehttp/promises (1.5.1 => 1.5.2)

Upgrading guzzlehttp/psr7 (2.2.1 => 2.4.1)

Upgrading illuminate/bus (v6.20.44 => v8.83.25)

Upgrading illuminate/cache (v6.20.44 => v8.83.25)

Locking illuminate/collections (v8.83.25)

Upgrading illuminate/config (v6.20.44 => v8.83.25)

Upgrading illuminate/console (v6.20.44 => v8.83.25)

Upgrading illuminate/container (v6.20.44 => v8.83.25)

Upgrading illuminate/contracts (v6.20.44 => v8.83.25)

Upgrading illuminate/database (v6.20.44 => v8.83.25)

Upgrading illuminate/events (v6.20.44 => v8.83.25)

Upgrading illuminate/filesystem (v6.20.44 => v8.83.25)

Upgrading illuminate/hashing (v6.20.44 => v8.83.25)

Locking illuminate/macroable (v8.83.25)

Upgrading illuminate/mail (v6.20.44 => v8.83.25)

Upgrading illuminate/pipeline (v6.20.44 => v8.83.25)

Upgrading illuminate/queue (v6.20.44 => v8.83.25)

Upgrading illuminate/session (v6.20.44 => v8.83.25)

Upgrading illuminate/support (v6.20.44 => v8.83.25)

Upgrading illuminate/translation (v6.20.44 => v8.83.25)

Upgrading illuminate/validation (v6.20.44 => v8.83.25)

Upgrading illuminate/view (v6.20.44 => v8.83.25)

Upgrading laminas/laminas-diactoros (1.8.7p2 => 2.19.0)

Upgrading laminas/laminas-escaper (2.6.1 => 2.12.0)

Upgrading laminas/laminas-httphandlerrunner (1.2.0 => 1.5.0)

Upgrading laminas/laminas-stratigility (3.2.2 => 3.9.0)

Upgrading laminas/laminas-zendframework-bridge (1.1.1 => 1.6.1)

Locking laravel/serializable-closure (v1.2.2)

Upgrading league/commonmark (1.6.7 => 2.3.5)

Locking league/config (v1.1.1)

Upgrading league/flysystem (1.1.9 => 1.1.10)

Upgrading matthiasmullie/minify (1.3.68 => 1.3.69)

Upgrading middlewares/base-path (v1.1.0 => v2.1.0)

Upgrading middlewares/base-path-router (v0.2.1 => v2.0.1)

Upgrading middlewares/request-handler (v1.4.0 => v2.0.2)

Upgrading middlewares/utils (v2.2.0 => v3.3.0)

Upgrading monolog/monolog (1.27.0 => 1.27.1)

Upgrading nesbot/carbon (2.58.0 => 2.62.1)

Locking nette/schema (v1.2.2)

Locking nette/utils (v3.2.8)

Upgrading psr/container (1.1.1 => 1.1.2)

Locking psr/event-dispatcher (1.0.0)

Locking ramsey/collection (1.2.2)

Locking ramsey/uuid (4.5.1)

Upgrading s9e/sweetdom (2.0.0 => 2.1.0)

Upgrading s9e/text-formatter (2.11.1 => 2.12.0)

Locking sycho/codecs-base64vlq (2.0.0)

Locking sycho/errors (3.0.0)

Locking sycho/json-api (v0.5.1)

Locking sycho/sourcemap (2.0.0)

Upgrading symfony/config (v4.4.42 => v5.4.11)

Upgrading symfony/console (v4.4.42 => v5.4.14)

Upgrading symfony/css-selector (v5.4.3 => v6.1.3)

Upgrading symfony/deprecation-contracts (v2.5.1 => v3.1.1)

Upgrading symfony/event-dispatcher (v4.4.42 => v5.4.9)

Upgrading symfony/event-dispatcher-contracts (v1.1.12 => v3.1.1)

Upgrading symfony/filesystem (v5.4.9 => v6.1.5)

Upgrading symfony/finder (v4.4.41 => v5.4.11)

Upgrading symfony/http-foundation (v4.4.42 => v5.4.14)

Upgrading symfony/mime (v5.4.9 => v5.4.14)

Upgrading symfony/polyfill-ctype (v1.25.0 => v1.26.0)

Upgrading symfony/polyfill-iconv (v1.25.0 => v1.26.0)

Locking symfony/polyfill-intl-grapheme (v1.26.0)

Upgrading symfony/polyfill-intl-idn (v1.25.0 => v1.26.0)

Locking symfony/polyfill-intl-messageformatter (v1.26.0)

Upgrading symfony/polyfill-intl-normalizer (v1.25.0 => v1.26.0)

Upgrading symfony/polyfill-mbstring (v1.25.0 => v1.26.0)

Upgrading symfony/polyfill-php72 (v1.25.0 => v1.26.0)

Upgrading symfony/polyfill-php73 (v1.25.0 => v1.26.0)

Upgrading symfony/polyfill-php80 (v1.25.0 => v1.26.0)

Upgrading symfony/polyfill-php81 (v1.25.0 => v1.26.0)

Upgrading symfony/process (v4.4.41 => v5.4.11)

Upgrading symfony/service-contracts (v2.5.1 => v2.5.2)

Locking symfony/string (v6.1.6)

Upgrading symfony/translation (v4.4.41 => v5.4.14)

Upgrading symfony/translation-contracts (v2.5.1 => v2.5.2)

Upgrading symfony/yaml (v4.4.37 => v5.4.14)

Upgrading tijsverkoyen/css-to-inline-styles (2.2.4 => 2.2.5)

Locking voku/portable-ascii (1.6.1)

Locking webmozart/assert (1.11.0)
Writing lock file
Installing dependencies from lock file
Package operations: 21 installs, 85 updates, 13 removals

Downloading axy/backtrace (2.0.0)

Downloading doctrine/event-manager (1.2.0)

Downloading doctrine/inflector (2.0.6)

Downloading symfony/polyfill-ctype (v1.26.0)

Downloading webmozart/assert (1.11.0)

Downloading dragonmantank/cron-expression (v3.3.2)

Downloading symfony/yaml (v5.4.14)

Downloading symfony/translation-contracts (v2.5.2)

Downloading symfony/polyfill-php80 (v1.26.0)

Downloading symfony/polyfill-mbstring (v1.26.0)

Downloading symfony/translation (v5.4.14)

Downloading symfony/polyfill-intl-messageformatter (v1.26.0)

Downloading symfony/polyfill-php72 (v1.26.0)

Downloading symfony/polyfill-intl-normalizer (v1.26.0)

Downloading symfony/polyfill-intl-idn (v1.26.0)

Downloading symfony/mime (v5.4.14)

Downloading symfony/polyfill-intl-grapheme (v1.26.0)

Downloading symfony/string (v6.1.6)

Downloading symfony/service-contracts (v2.5.2)

Downloading symfony/polyfill-php73 (v1.26.0)

Downloading symfony/console (v5.4.14)

Downloading symfony/polyfill-php81 (v1.26.0)

Downloading symfony/filesystem (v6.1.5)

Downloading symfony/config (v5.4.11)

Downloading sycho/errors (3.0.0)

Downloading sycho/codecs-base64vlq (2.0.0)

Downloading sycho/sourcemap (2.0.0)

Downloading sycho/json-api (v0.5.1)

Downloading s9e/sweetdom (2.1.0)

Downloading s9e/text-formatter (2.12.0)

Downloading nesbot/carbon (2.62.1)

Downloading monolog/monolog (1.27.1)

Downloading matthiasmullie/minify (1.3.69)

Downloading league/flysystem (1.1.10)

Downloading laminas/laminas-escaper (2.12.0)

Downloading laminas/laminas-stratigility (3.9.0)

Downloading guzzlehttp/psr7 (2.4.1)

Downloading laminas/laminas-diactoros (2.19.0)

Downloading laminas/laminas-zendframework-bridge (1.6.1)

Downloading illuminate/collections (v8.83.25)

Downloading illuminate/support (v8.83.25)

Downloading symfony/finder (v5.4.11)

Downloading symfony/http-foundation (v5.4.14)

Downloading illuminate/validation (v8.83.25)

Downloading symfony/process (v5.4.11)

Downloading brick/math (0.10.2)

Downloading ramsey/uuid (4.5.1)

Downloading laravel/serializable-closure (v1.2.2)

Downloading illuminate/database (v8.83.25)

Downloading illuminate/queue (v8.83.25)

Downloading symfony/css-selector (v6.1.3)

Downloading tijsverkoyen/css-to-inline-styles (2.2.5)

Downloading symfony/polyfill-iconv (v1.26.0)

Downloading nette/utils (v3.2.8)

Downloading league/commonmark (2.3.5)

Downloading illuminate/cache (v8.83.25)

Downloading guzzlehttp/promises (1.5.2)

Downloading guzzlehttp/guzzle (7.5.0)

Downloading flarum/core (v1.5.0)

Downloading flarum/flags (v1.5.0)

Downloading flarum/approval (v1.5.0)

Downloading flarum/bbcode (v1.5.0)

Downloading flarum/emoji (v1.5.0)

Downloading flarum/lang-english (v1.5.0)

Downloading flarum/likes (v1.5.0)

Downloading flarum/lock (v1.5.0)

Downloading flarum/markdown (v1.5.0)

Downloading flarum/mentions (v1.5.0)

Downloading flarum/pusher (v1.5.0)

Downloading flarum/statistics (v1.5.1)

Downloading flarum/sticky (v1.5.0)

Downloading flarum/subscriptions (v1.5.0)

Downloading flarum/suspend (v1.5.0)

Downloading flarum/tags (v1.5.0)

Downloading fof/spamblock (1.0.2)

Removing tobscure/json-api (v0.3.0)

Removing symfony/debug (v4.4.41)

Removing paragonie/random_compat (v9.99.100)

Removing league/oauth2-github (2.0.0)

Removing league/oauth2-facebook (2.0.5)

Removing league/oauth2-client (2.6.1)

Removing league/oauth1-client (v1.10.1)

Removing flarum/auth-twitter (v0.1.0-beta.13)

Removing flarum/auth-github (v0.1.0-beta.13)

Removing flarum/auth-facebook (v0.1.0-beta.13)

Removing axy/sourcemap (0.1.5)

Removing axy/errors (1.0.5)

Removing axy/codecs-base64vlq (1.0.1)

Upgrading axy/backtrace (1.0.7 => 2.0.0): Extracting archive

Upgrading dflydev/fig-cookies (v2.0.3 => v3.0.0): Extracting archive

Upgrading doctrine/event-manager (1.1.1 => 1.2.0): Extracting archive

Upgrading doctrine/inflector (2.0.4 => 2.0.6): Extracting archive

Upgrading symfony/polyfill-ctype (v1.25.0 => v1.26.0): Extracting archive

Installing webmozart/assert (1.11.0): Extracting archive

Installing dragonmantank/cron-expression (v3.3.2): Extracting archive

Upgrading symfony/deprecation-contracts (v2.5.1 => v3.1.1): Extracting archive

Upgrading symfony/yaml (v4.4.37 => v5.4.14): Extracting archive

Upgrading symfony/translation-contracts (v2.5.1 => v2.5.2): Extracting archive

Upgrading symfony/polyfill-php80 (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/polyfill-mbstring (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/translation (v4.4.41 => v5.4.14): Extracting archive

Installing symfony/polyfill-intl-messageformatter (v1.26.0): Extracting archive

Upgrading symfony/polyfill-php72 (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/polyfill-intl-normalizer (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/polyfill-intl-idn (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/mime (v5.4.9 => v5.4.14): Extracting archive

Installing psr/event-dispatcher (1.0.0): Extracting archive

Upgrading symfony/event-dispatcher-contracts (v1.1.12 => v3.1.1): Extracting archive

Upgrading symfony/event-dispatcher (v4.4.42 => v5.4.9): Extracting archive

Installing symfony/polyfill-intl-grapheme (v1.26.0): Extracting archive

Installing symfony/string (v6.1.6): Extracting archive

Upgrading psr/container (1.1.1 => 1.1.2): Extracting archive

Upgrading symfony/service-contracts (v2.5.1 => v2.5.2): Extracting archive

Upgrading symfony/polyfill-php73 (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/console (v4.4.42 => v5.4.14): Extracting archive

Upgrading symfony/polyfill-php81 (v1.25.0 => v1.26.0): Extracting archive

Upgrading symfony/filesystem (v5.4.9 => v6.1.5): Extracting archive

Upgrading symfony/config (v4.4.42 => v5.4.11): Extracting archive

Installing sycho/errors (3.0.0): Extracting archive

Installing sycho/codecs-base64vlq (2.0.0): Extracting archive

Installing sycho/sourcemap (2.0.0): Extracting archive

Installing sycho/json-api (v0.5.1): Extracting archive

Upgrading s9e/sweetdom (2.0.0 => 2.1.0): Extracting archive

Upgrading s9e/text-formatter (2.11.1 => 2.12.0): Extracting archive

Upgrading nesbot/carbon (2.58.0 => 2.62.1): Extracting archive

Upgrading monolog/monolog (1.27.0 => 1.27.1): Extracting archive

Upgrading middlewares/utils (v2.2.0 => v3.3.0): Extracting archive

Upgrading middlewares/request-handler (v1.4.0 => v2.0.2): Extracting archive

Upgrading middlewares/base-path-router (v0.2.1 => v2.0.1): Extracting archive

Upgrading middlewares/base-path (v1.1.0 => v2.1.0): Extracting archive

Upgrading matthiasmullie/minify (1.3.68 => 1.3.69): Extracting archive

Upgrading league/flysystem (1.1.9 => 1.1.10): Extracting archive

Upgrading laminas/laminas-escaper (2.6.1 => 2.12.0): Extracting archive

Upgrading laminas/laminas-stratigility (3.2.2 => 3.9.0): Extracting archive

Upgrading guzzlehttp/psr7 (2.2.1 => 2.4.1): Extracting archive

Upgrading laminas/laminas-diactoros (1.8.7p2 => 2.19.0): Extracting archive

Upgrading laminas/laminas-zendframework-bridge (1.1.1 => 1.6.1): Extracting archive

Upgrading laminas/laminas-httphandlerrunner (1.2.0 => 1.5.0): Extracting archive

Installing voku/portable-ascii (1.6.1): Extracting archive

Installing illuminate/macroable (v8.83.25): Extracting archive

Upgrading illuminate/contracts (v6.20.44 => v8.83.25): Extracting archive

Installing illuminate/collections (v8.83.25): Extracting archive

Upgrading illuminate/support (v6.20.44 => v8.83.25): Extracting archive

Upgrading symfony/finder (v4.4.41 => v5.4.11): Extracting archive

Upgrading illuminate/filesystem (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/container (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/pipeline (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/bus (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/events (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/view (v6.20.44 => v8.83.25): Extracting archive

Upgrading symfony/http-foundation (v4.4.42 => v5.4.14): Extracting archive

Upgrading illuminate/translation (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/validation (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/session (v6.20.44 => v8.83.25): Extracting archive

Upgrading symfony/process (v4.4.41 => v5.4.11): Extracting archive

Installing ramsey/collection (1.2.2): Extracting archive

Installing brick/math (0.10.2): Extracting archive

Installing ramsey/uuid (4.5.1): Extracting archive

Installing laravel/serializable-closure (v1.2.2): Extracting archive

Upgrading illuminate/database (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/console (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/queue (v6.20.44 => v8.83.25): Extracting archive

Upgrading symfony/css-selector (v5.4.3 => v6.1.3): Extracting archive

Upgrading tijsverkoyen/css-to-inline-styles (2.2.4 => 2.2.5): Extracting archive

Upgrading symfony/polyfill-iconv (v1.25.0 => v1.26.0): Extracting archive

Installing nette/utils (v3.2.8): Extracting archive

Installing nette/schema (v1.2.2): Extracting archive

Installing dflydev/dot-access-data (v3.0.1): Extracting archive

Installing league/config (v1.1.1): Extracting archive

Upgrading league/commonmark (1.6.7 => 2.3.5): Extracting archive

Upgrading illuminate/mail (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/hashing (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/config (v6.20.44 => v8.83.25): Extracting archive

Upgrading illuminate/cache (v6.20.44 => v8.83.25): Extracting archive

Upgrading guzzlehttp/promises (1.5.1 => 1.5.2): Extracting archive

Upgrading guzzlehttp/guzzle (7.4.3 => 7.5.0): Extracting archive

Upgrading franzl/whoops-middleware (0.4.1 => 2.0.0): Extracting archive

Upgrading flarum/core (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/flags (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/approval (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/bbcode (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/emoji (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/lang-english (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/likes (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/lock (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/markdown (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/mentions (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/pusher (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/statistics (v0.1.0-beta.15 => v1.5.1): Extracting archive

Upgrading flarum/sticky (v0.1.0-beta.15.1 => v1.5.0): Extracting archive

Upgrading flarum/subscriptions (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/suspend (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading flarum/tags (v0.1.0-beta.15 => v1.5.0): Extracting archive

Upgrading fof/spamblock (0.4.0 => 1.0.2): Extracting archive
11 package suggestions were added by new dependencies, use composer suggest to see details.
Package swiftmailer/swiftmailer is abandoned, you should avoid using it. Use symfony/mailer instead.
Generating optimized autoload files
73 packages you are using are looking for funding.
Use the composer fund command to find out more!
No security vulnerability advisories found

But then flarum migrate fails with a PHP error, and the forum is not working anymore (Internal Server Error)

[root@server forum.somedomain.net]# php flarum migrate
PHP Parse error: syntax error, unexpected '=' in /var/www/vhosts/somedomain.net/forum.somedomain.net/vendor/symfony/string/Resources/functions.php on line 34

So what is this error? Apparently related to running PHP version under 7.4

The line 34 error in vendor\symfony\string\Resources\functions.php

$string ??= '';
This is a Null Coalescing Assignment Operator - https://wiki.php.net/rfc/null_coalesce_equal_operator#:~:text=coalescing%20operator%20being%20a%20comparison,not%20null%2C%20nothing%20is%20made.

As stated in the link above this has been implemented in PHP 7.4. You will need to update your PHP version to 7.4

What the heck is going on here? Everything says I'm running PHP 7.4 but the errors I'm facing are related to PHP 7.2 ...