Following on from T226752 after https://github.com/wikimedia/integration-config/commit/9988d30de8151dd59f387d2e6032b4b20f9d6644 ext-gmp should be there...
https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/WebAuthn/+/508788/ https://integration.wikimedia.org/ci/job/mwext-php72-phan-docker/1219/console
```
19:56:23 [178.3MB/1.87s] Your requirements could not be resolved to an installable set of packages.
19:56:23 [178.3MB/1.87s]
19:56:23 Problem 1
19:56:23 - spomky-labs/cbor-php v1.0.3 requires ext-gmp * -> the requested PHP extension gmp is missing from your system.
19:56:23 - spomky-labs/cbor-php v1.0.2 requires ext-gmp * -> the requested PHP extension gmp is missing from your system.
19:56:23 - web-auth/webauthn-lib v1.2.0 requires spomky-labs/cbor-php ^1.0.2 -> satisfiable by spomky-labs/cbor-php[v1.0.2, v1.0.3].
19:56:23 - Installation request for web-auth/webauthn-lib v1.2.0 -> satisfiable by web-auth/webauthn-lib[v1.2.0].
19:56:23
19:56:23 To enable extensions, verify that they are enabled in your .ini files:
19:56:23 - /etc/php/7.2/cli/php.ini
19:56:23 - /etc/php/7.2/cli/conf.d/10-opcache.ini
19:56:23 - /etc/php/7.2/cli/conf.d/10-pdo.ini
19:56:23 - /etc/php/7.2/cli/conf.d/15-xml.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-calendar.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-ctype.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-curl.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-dba.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-dom.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-exif.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-fileinfo.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-ftp.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-gettext.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-iconv.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-igbinary.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-json.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-mbstring.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-pdo_sqlite.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-phar.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-posix.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-readline.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-redis.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-shmop.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-simplexml.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-sockets.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-sqlite3.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-sysvmsg.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-sysvsem.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-sysvshm.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-tokenizer.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-wddx.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-xmlreader.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-xmlwriter.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-xsl.ini
19:56:23 - /etc/php/7.2/cli/conf.d/20-zip.ini
19:56:23 You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.
```