Herokuで、DBアクセスするPHPのアプリ動かすと、call_user_func関数がうんたらというエラーが出て困った話 ref: http://qiita.com/yonell/items/fbed7f66d804794a42b4

composer.json

--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,8 @@
                "slim/extras": "2.0.*",
                "twig/twig": "1.*",
                "Respect/Validation" : "0.5.*",
-               "illuminate/database" : "4.0.*"
+               "illuminate/database" : "4.0.*",
+               "ext-mbstring": "*"
        },
        "autoload": {
                "psr-0": {"":"lib/"}

file0.txt

Slim Application Error
The application could not run because of the following error:

Details

Type: ErrorException
Code: 2
Message: call_user_func() expects parameter 1 to be a valid callback, function 'mb_strtolower' not found or invalid function name
File: /app/vendor/illuminate/support/Illuminate/Support/Pluralizer.php
Line: 234
Trace

#0 [internal function]: Slim\Slim::handleErrors(2, 'call_user_func(...', '/app/vendor/ill...', 234, Array)
# 以下略

file1.txt

--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,8 @@
                "slim/extras": "2.0.*",
                "twig/twig": "1.*",
                "Respect/Validation" : "0.5.*",
-               "illuminate/database" : "4.0.*"
+               "illuminate/database" : "4.0.*",
+               "ext-mbstring": "*"
        },
        "autoload": {
                "psr-0": {"":"lib/"}