Composer 2 slow because it parses git branches

[ihor-sviziev]

My composer.json:

{
    "name": "root/html",
    "type": "project",
    "authors": [
        {
            "name": "a",
            "email": "a@example.com"
        }
    ],
    "require": {}
}

Output of composer diagnose:

Checking composer.json: WARNING
No license specified, it is recommended to do so. For closed-source software you may use "proprietary" as license.
Checking platform settings: OK
Checking git settings: OK
Checking http connectivity to packagist: OK
Checking https connectivity to packagist: OK
Checking github.com rate limit: OK
Checking disk free space: OK
Checking pubkeys:
Tags Public Key Fingerprint: 57815BA2 7E54DC31 7ECC7CC5 573090D0  87719BA6 8F3BB723 4E5D42D0 84A14642
Dev Public Key Fingerprint: 4AC45767 E5EC2265 2F0C1167 CBBB8A2B  0C708369 153E328C AD90147D AFE50952
OK
Checking composer version: OK
Composer version: 2.1.5
PHP version: 7.4.22
PHP binary path: /usr/bin/php
OpenSSL version: OpenSSL 1.1.1g FIPS  21 Apr 2020
cURL version: 7.61.1 libz 1.2.11 ssl OpenSSL/1.1.1g
zip: extension present, unzip present, 7-Zip not available

When I run this command: composer -V -vvv

time composer --version -vvv

I get the following output:

Reading ./composer.json (/var/www/html/composer.json)
Loading config file /home/www-data/.composer/auth.json
Loading config file ./composer.json (/var/www/html/composer.json)
Checked CA file /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem: valid
Executing command (/var/www/html): git branch -a --no-color --no-abbrev -v
Executing command (/var/www/html): git rev-list 2.5-develop..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list 2.4-develop..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list 2.3.7-release..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list 2.3.7-Optimize_QuoteIdToMaskedQuoteId_model_and_fix_infinite_loop..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list 2.3.6-p1..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list 2.3..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.5-develop..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.4-develop..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.4..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.3.7-release..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.3.7-patch-33723..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.3.7-patch-33706..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.3.7-patch-33704..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.3.7-patch-33664..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.3..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.2..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.1..replace-not-needed-polyfills
Executing command (/var/www/html): git rev-list remotes/origin/2.0..replace-not-needed-polyfills
Reading /home/www-data/.composer/composer.json
Loading config file /home/www-data/.composer/auth.json
Loading config file /home/www-data/.composer/composer.json (/home/www-data/.composer/composer.json)
Loading config file /home/www-data/.composer/auth.json
Reading /home/www-data/.composer/auth.json
Reading /home/www-data/.composer/vendor/composer/installed.json
Running 2.1.5 (2021-07-23 10:35:47) with PHP 7.4.22 on Linux / 5.4.72-microsoft-standard-WSL2
Composer version 2.1.5 2021-07-23 10:35:47

real    0m1.193s
user    0m1.011s
sys     0m0.431s

And I expected this to happen:
I expect that composer or composer --version will be near 0.1 second, similar to composer 1:
On composer1 this works way faster:

$ time composer1 --version -vvv
Reading ./composer.json
Loading config file /home/www-data/.composer/auth.json
Loading config file ./composer.json
Checked CA file /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem: valid
Executing command (/var/www/html): git branch -a --no-color --no-abbrev -v
Reading /home/www-data/.composer/composer.json
Loading config file /home/www-data/.composer/auth.json
Loading config file /home/www-data/.composer/composer.json
Loading config file /home/www-data/.composer/auth.json
Reading /home/www-data/.composer/auth.json
Reading /home/www-data/.composer/vendor/composer/installed.json
Running 1.10.22 (2021-04-27 13:10:45) with PHP 7.4.22 on Linux / 5.4.72-microsoft-standard-WSL2
Composer version 1.10.22 2021-04-27 13:10:45

real    0m0.102s
user    0m0.092s
sys     0m0.000s

[ihor-sviziev]

@Seldaek, thx for the quick fix!