Magento 2 - "Installation failed" with composer

Question

Magento 2.4.3-pl - PHP 7.4.30

When trying to install any new extension using Composer I receive "Installation failed" messages, like so:

Installation failed, reverting ./composer.json and ./composer.lock to their original content.
ubuntu@xadmin:/home/[USER]/web/xdev.DOMAIN.co.uk/public_html$ composer require firebear/importexport-msi:^1.1.3 --with-all-dependencies
./composer.json has been updated
Running composer update firebear/importexport-msi --with-all-dependencies
Loading composer repositories with package information
In Laminas\DependencyPlugin\DependencyRewriterV2::onPrePoolCreate
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Root composer.json requires firebear/importexport-msi ^1.1.3 -> satisfiable by firebear/importexport-msi[1.1.3].
    - firebear/importexport-msi 1.1.3 requires firebear/importexport >=3.0.0 -> found firebear/importexport[3.8.0] in the lock file but not in remote repositories, make sure you avoid updating this package to keep the one from the lock file.
  Problem 2
    - php-http/guzzle7-adapter 1.0.0 requires guzzlehttp/guzzle ^7.0 -> found guzzlehttp/guzzle[7.0.0, ..., 7.5.0] but these were not loaded, likely because it conflicts with another require.
    - develodesign/designer 2.4.0 requires php-http/guzzle7-adapter ^1.0 -> satisfiable by php-http/guzzle7-adapter[1.0.0].
    - Root composer.json requires develodesign/designer 2.4.0 -> satisfiable by develodesign/designer[2.4.0].

As you can see, one of the extensions causing issues is firebear/importexport-msi, which is currently disabled and, if I remember correctly, the original dev had issues with too. I think he said he'd had to "install it manually". Pretty certain that is the main problem.

So my questions: 1 Is the manual install the problem? If so, what do I need to do to clear that out of the system?

2 How can I get round develodesign/designer needing a lower version of Guzzle than everything else? (although I suspect that clearing composer would allow me to get an updated version of develodesign/designer)

Thanks in advance.

Answer 1

The best solution in this situation is that firstly you need to remove the firebear and the develodesign extension using composer, after that try to reinstall those extensions, it will install the latest version and has a dependency added. After that try to install your new extension.

NOTE:- Before doing these, take a backup of composer.json, composer.lock, and auth.json files and try to do it in the local environment.