GuzzleHttp cannot be installed on Laravel 5.8

Question

I'm using Laravel 5.8 and I want to install the GuzzleHttp package.

First I tried running composer require guzzlehttp/guzzle but I got this error:

Problem 1
    - guzzlehttp/guzzle[7.4.0, ..., 7.4.x-dev] require guzzlehttp/promises ^1.5 -> found guzzlehttp/promises[dev-master, 1.5.0, 1.5.1, 1.5.x-dev (alias of dev-master)] but the package is fixed to 1.4.1 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
    - Root composer.json requires guzzlehttp/guzzle ^7.4 -> satisfiable by guzzlehttp/guzzle[7.4.0, ..., 7.4.x-dev].

Then I tried to install a downgraded version, so I ran the following command:

composer require "guzzlehttp/guzzle:~5.3"

But I get this error:

Problem 1
    - Root composer.json requires guzzlehttp/guzzle ~5.3, found guzzlehttp/guzzle[5.3.0, ..., 5.3.x-dev] but these were not loaded, likely because it conflicts with another require.
  Problem 2
    - anhskohbo/no-captcha is locked to version 3.3.0 and an update of this package was not requested.
    - anhskohbo/no-captcha 3.3.0 requires guzzlehttp/guzzle ^6.2|^7.0 -> found guzzlehttp/guzzle[dev-master, 6.2.0, ..., 6.5.x-dev, 7.0.0-beta. 1, ..., 7.4.x-dev (alias of dev-master)] but it conflicts with your root composer.json require (~5.3).

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

So what’s the problem here? How to properly install Laravel 5.8 version of GuzzleHttp?

Answer 1

Try adding the -w flag to the command:

Composer requires guzzlehttp/guzzle -w

One of your other dependencies requires guzzlehttp/promises, which is currently locked at 1.4.1 in your composer.lock

The

-w flag tells Composer that dependencies can be updated when new dependencies are installed.

If this doesn't work then you can try using the -W flag.