herokuにpushすると謎のエラーが出た話

$ git push heroku master

remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> PHP app detected
remote: -----> Bootstrapping...
remote: -----> Installing platform packages...
remote:        - php (7.2.8)
remote:        - ext-gd (bundled with php)
remote:        - ext-mbstring (bundled with php)
remote:        - nginx (1.8.1)
remote:        - apache (2.4.34)
remote: /app/tmp/buildpacks/2eb21e9db12e182f49d4d2f512fbbb1b5c0e2f2cc7316a571d4c31b476916dc7f9372d5a597490761325ac6b221f8f381804151a7b10729a06a6f76e022e52de/export: line 1: export: `SSL/TLS': not a valid identifier
remote: /app/tmp/buildpacks/2eb21e9db12e182f49d4d2f512fbbb1b5c0e2f2cc7316a571d4c31b476916dc7f9372d5a597490761325ac6b221f8f381804151a7b10729a06a6f76e022e52de/export: line 1: export: `disabled.': not a valid identifier
remote:  !     Push rejected, failed to compile PHP app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...

アレコレしても全然直らない
で、最終的に空のリポジトリ作って1ファイルずつ調べたら原因はここでした

composer.json

    "config": {
        "disable-tls": true, ← コレ！！！
        "secure-http": false,
        "vendor-dir": "data/vendor",
        "platform": {
            "php": "5.4"
        }
    },

“disable-tls”: false に直したら解決、時間返してくれ。。。