<p>I found <a href="https://github.com/craftcms/cms/issues/4927#issuecomment-575360828" rel="nofollow noreferrer">the fix here</a></p>
<p><code>composer install --ignore-platform-reqs</code></p>

CC BY-SA 4.0
2021-02-13T01:04:51.117Z
2021-02-13T01:04:51.117Z
doctorgloom
<p>I'm new to Craft so maybe I'm doing something dumb, but I can't get past this error screen when trying to update to 3.6:</p>
<pre><code>Composer output: Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

Problem 1
- Can only install one of: yiisoft/yii2[2.0.38, 2.0.40].
- Can only install one of: yiisoft/yii2[2.0.40, 2.0.38].
- craftcms/cms 3.6.5.1 requires yiisoft/yii2 ~2.0.40.0 -&gt; satisfiable by yiisoft/yii2[2.0.40].
- Installation request for craftcms/cms 3.6.5.1 -&gt; satisfiable by craftcms/cms[3.6.5.1].
- Installation request for yiisoft/yii2 (installed at 2.0.38) -&gt; satisfiable by yiisoft/yii2[2.0.38].

Running update with --no-dev does not mean require-dev is ignored, it just means the packages will not be installed. If dev requirements are blocking the update you have to resolve those problems.
</code></pre>
<p>I deleted the composer.lock file based on some threads I found here, and I tried running <code>composer update</code> from the terminal and it did reduce a much longer error message down to this one, but still no joy.</p>
<p>I'm developing locally on MAMP, 3.5.x was running great.</p>
<p>My <code>composer.json</code>:</p>
<pre><code>{
  &quot;require&quot;: {
    &quot;craftcms/cms&quot;: &quot;3.5.18&quot;,
    &quot;craftcms/contact-form&quot;: &quot;2.2.7&quot;,
    &quot;craftcms/feed-me&quot;: &quot;4.3.4&quot;,
    &quot;craftcms/mailgun&quot;: &quot;1.4.3&quot;,
    &quot;craftcms/redactor&quot;: &quot;2.8.5&quot;,
    &quot;vlucas/phpdotenv&quot;: &quot;^3.4.0&quot;
  },
  &quot;require-dev&quot;: {
    &quot;yiisoft/yii2-shell&quot;: &quot;^2.0.3&quot;
  },
  &quot;autoload&quot;: {
    &quot;psr-4&quot;: {
      &quot;modules\\&quot;: &quot;modules/&quot;
    }
  },
  &quot;config&quot;: {
    &quot;sort-packages&quot;: true,
    &quot;optimize-autoloader&quot;: true,
    &quot;platform&quot;: {
      &quot;php&quot;: &quot;7.2.5&quot;
    }
  },
  &quot;scripts&quot;: {
    &quot;post-root-package-install&quot;: [
      &quot;@php -r \&quot;file_exists('.env') || copy('.env.example', '.env');\&quot;&quot;
    ]
  }
}
</code></pre>

CC BY-SA 4.0
2021-02-13T00:37:24.000Z
If you put a ^ in front of all of the dependencies (i.e. `"craftcms/cms": "^3.5.18", "craftcms/contact-form": "^2.2.7",`, etc.) then run `composer update`, does that help?
Brad Bell
CC BY-SA 4.0
2021-02-13T00:54:24.220Z
Tried but now I'm getting the error: Install or enable PHP's zip extension. Quick search suggests it's not available on MAMP I guess, so maybe that's the problem?
doctorgloom
CC BY-SA 4.0
2021-02-13T01:02:04.650Z
Just found the fix: composer install --ignore-platform-reqs
doctorgloom
<updating>
Craft 3.6 Upgrade errors - can only install one of yiisoft/yii2 (and other errors)
# Craft 3.6 Upgrade errors - can only install one of yiisoft/yii2 (and other errors)

(Asked by: username_0 on 2021-02-12)

I'm new to Craft so maybe I'm doing something dumb, but I can't get past this error screen when trying to update to 3.6:
Composer output: Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

Problem 1
- Can only install one of: yiisoft/yii2[2.0.38, 2.0.40].
- Can only install one of: yiisoft/yii2[2.0.40, 2.0.38].
- craftcms/cms 3.6.5.1 requires yiisoft/yii2 ~2.0.40.0 -> satisfiable by yiisoft/yii2[2.0.40].
- Installation request for craftcms/cms 3.6.5.1 -> satisfiable by craftcms/cms[3.6.5.1].
- Installation request for yiisoft/yii2 (installed at 2.0.38) -> satisfiable by yiisoft/yii2[2.0.38].

Running update with --no-dev does not mean require-dev is ignored, it just means the packages will not be installed. If dev requirements are blocking the update you have to resolve those problems.

I deleted the composer.lock file based on some threads I found here, and I tried running composer update from the terminal and it did reduce a much longer error message down to this one, but still no joy.
I'm developing locally on MAMP, 3.5.x was running great.
My composer.json:
{
  "require": {
    "craftcms/cms": "3.5.18",
    "craftcms/contact-form": "2.2.7",
    "craftcms/feed-me": "4.3.4",
    "craftcms/mailgun": "1.4.3",
    "craftcms/redactor": "2.8.5",
    "vlucas/phpdotenv": "^3.4.0"
  },
  "require-dev": {
    "yiisoft/yii2-shell": "^2.0.3"
  },
  "autoload": {
    "psr-4": {
      "modules\\": "modules/"
    }
  },
  "config": {
    "sort-packages": true,
    "optimize-autoloader": true,
    "platform": {
      "php": "7.2.5"
    }
  },
  "scripts": {
    "post-root-package-install": [
      "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
    ]
  }
}

**Tags:** updating
> **Comments:**
> **username_1**: If you put a ^ in front of all of the dependencies (i.e. `"craftcms/cms": "^3.5.18", "craftcms/contact-form": "^2.2.7",`, etc.) then run `composer update`, does that help?  
> **username_0**: Tried but now I'm getting the error: Install or enable PHP's zip extension. Quick search suggests it's not available on MAMP I guess, so maybe that's the problem?  
> **username_0**: Just found the fix: composer install --ignore-platform-reqs  

---

## 1 answers

### Answer by username_0 on 2021-02-13. Score: 2

I found [the fix here](https://github.com/craftcms/cms/issues/4927#issuecomment-575360828)

`composer install --ignore-platform-reqs`


---

