Description:
In hhvm, as of approximately a month or so ago, the compiled binary guesses /usr/lib/sendmail -t -i as the sendmail path, where it guessed /usr/bin/sendmail -t -i before. This seems like a new problem, although I'm actually not sure if it's due to how its packaged. If this is a bug and it cannot be compiled in through the configuration then it would be easy enough to add :

hhvm.mail.mail_path = "/usr/bin/sendmail -t -i"

to the bottom of /etc/hhvm/php.ini. I figured it's a bug because the package abruptly changed this behavior as of about a month ago, and on the hhvm website it says it will attempt to guess the sendmail path at compile time.

Additional info:
* package version(s): hhvm 3.5.0-1
* config and/or log files etc.


Steps to reproduce:
1. Install hhvm from community.
2. Create a file test.php with the following contents:

<?php
$test = mail("user@example.com", "test mail", "just a test mail. Please ignore." "from:yourmail@mail.com", false);
echo $test;
?>


note to replace the relevant email address with appropriate ones for your situation.
3. Note that hhvm returns something like "/usr/lib/sendmail: no such file or directory." if you have your sendmail installed under /usr/bin/sendmail.