composer installed.json" does not contain valid JSON - php

Question

I upgraded laravel 5.4 to laravel 5.5 according to the official documents, and then executed composer update, which returned this error
- Installing theseer/tokenizer (1.2.0): Extracting archive
- Installing sebastian/code-unit-reverse-lookup (1.0.2): Extracting archive
- Installing phpunit/php-code-coverage (5.3.2): Extracting archive
- Installing phpspec/prophecy (v1.10.3): Extracting archive
- Installing phar-io/version (1.0.1): Extracting archive
- Installing phar-io/manifest (1.0.1): Extracting archive
- Installing myclabs/deep-copy (1.10.2): Extracting archive
- Installing phpunit/phpunit (6.5.14): Extracting archive
- Installing predis/predis (v1.1.7): Extracting archive
Package jakub-onderka/php-console-color is abandoned, you should avoid using it. Use php-parallel-lint/php-console-color instead.
Package jakub-onderka/php-console-highlighter is abandoned, you should avoid using it. Use php-parallel-lint/php-console-highlighter instead.
Package mtdowling/cron-expression is abandoned, you should avoid using it. Use dragonmantank/cron-expression instead.
Package fzaninotto/faker is abandoned, you should avoid using it. No replacement was suggested.
Package phpunit/php-token-stream is abandoned, you should avoid using it. No replacement was suggested.
Package phpunit/phpunit-mock-objects is abandoned, you should avoid using it. No replacement was suggested.
Generating optimized autoload files
[Seld\JsonLint\ParsingException]
"/home/vagrant/work/exports-api/vendor/composer/installed.json" does not co
ntain valid JSON
Parse error on line 1:
^
Expected one of: 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '['
this is my composer.json
{
"name": "laravel/laravel",
"description": "The Laravel Framework.",
"keywords": ["framework", "laravel"],
"license": "MIT",
"type": "project",
"require": {
"php": ">=5.6.4",
"laravel/framework": "5.5.*",
"laravel/tinker": "~1.0",
"predis/predis": "^1.1"
},
"require-dev": {
"fzaninotto/faker": "~1.4",
"mockery/mockery": "0.9.*",
"phpunit/phpunit": "~6.0",
"filp/whoops": "~2.0"
},
"autoload": {
"classmap": [
"database"
],
"psr-4": {
"App\\": "app/"
}
},
"autoload-dev": {
"psr-4": {
"Tests\\": "tests/"
}
},
"scripts": {
"post-root-package-install": [
"php -r \"file_exists('.env') || copy('.env.example', '.env');\""
],
"post-create-project-cmd": [
"php artisan key:generate"
],
"post-install-cmd": [
"Illuminate\\Foundation\\ComposerScripts::postInstall",
"php artisan optimize"
],
"post-update-cmd": [
"Illuminate\\Foundation\\ComposerScripts::postUpdate",
"php artisan optimize"
],
"post-autoload-dump": [
"Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
"#php artisan package:discover"
]
},
"config": {
"preferred-install": "dist",
"sort-packages": true,
"optimize-autoloader": true
}
}
Then I'll check the file "/home/vagrant/work/exports-api/vendor/composer/installed.json" It's a blank, nothing
Supplementary notes
Before the update, there was something in installed.json, and composer update became blank. Now, the composer operation under this project will return this error

Answer 1

I changed the composer version from 2.0 to 1.0 to solve the problem