Drush 8.1.15 install fails with php 7.2.2

[ryanaslett]

Howdy all. So, d7 doesnt work with php 7.2, or at least throws a lot of exceptions for deprecated each() and count() of non-countables. Except I cannot run a drush si using 8.1.15 for a d7 site on drupalci, thus we cant really fix these issues without a version of drush that will work. For some reason, the error messages I get are the following:

testbot:drupaltestbotpw@172.18.0.4/jenkins_drupal_d7_61404 --clean-url=0 --account-name=admin --account-pass=drupal --account-mail=admin@example.com
You are about to CREATE the 'jenkins_drupal_d7_61404' database. Do you want to continue? (y/n): y
Starting Drupal installation. This takes a while. Consider using the --notify global option. [ok]
PHP Fatal error: Uncaught Error: Call to undefined function cache_get() in /var/www/html/includes/module.inc:754
Stack trace:
#0 /var/www/html/includes/module.inc(954): module_implements('system_theme_in...')
#1 /var/www/html/modules/system/system.module(2511): module_invoke_all('system_theme_in...')
#2 /var/www/html/includes/theme.inc(798): _system_rebuild_theme_data()
#3 /var/www/html/includes/theme.maintenance.inc(57): list_themes()
#4 /var/www/html/includes/bootstrap.inc(2872): _drupal_maintenance_theme()
#5 /var/www/html/includes/errors.inc(179): drupal_maintenance_theme()
#6 /var/www/html/includes/bootstrap.inc(2609): _drupal_log_error(Array, true)
#7 [internal function]: _drupal_exception_handler(Object(Error))
#8 {main}
thrown in /var/www/html/includes/module.inc on line 754
Drush command terminated abnormally due to an unrecoverable error.

I was able to install the site manually, and then run the tests, but drupalci has to use drush si to create a testable site.

[Chi-teck]

This is related to https://bugs.php.net/bug.php?id=75227

Starting Drupal installation. This takes a while. Consider using the --notify global option.

Seems like the message is sent before Drupal bootstrap process has begun, so ini_set fails to set some session settings. The simplest workaround is suppressing the output with --quiet option.

[ryanaslett]

What do headers have to do with a CLI php script? Im confused as to how that relates.

[greg-1-anderson]

Call to undefined function cache_get() looks more like a problem bootstrapping Drupal prior to the site-install to me, but I haven't had a chance to look at it yet.

[Chi-teck]

What do headers have to do with a CLI php script?

That is another PHP bug.
https://bugs.php.net/bug.php?id=42197

[Chi-teck]

One more solution to consider is printing this message conditionally for PHP < 7.2
https://github.com/drush-ops/drush/blob/8.1.15/commands/core/drupal/site_install_7.inc#L85

[greg-1-anderson]

@Chi Have you confirmed that commenting out the message allows site-install to work correctly? A while ago we switched drush_print to use fwrite instead of print or echo, as that method apparently did not interact with the php headers. Is that perhaps no longer the case in php 7.2?

I'll run some tests and see if I can figure anything out about this.

[Chi-teck]

@greg-1-anderson Turns out the error was caused by another message.

You are about to DROP all tables in your '<table_mane>' database. Do you want to continue? (y/n):

Commenting out these three lines did the job for me.
https://github.com/drush-ops/drush/blob/8.1.15/commands/core/site_install.drush.inc#L159-L161

[Chi-teck]

Starting Drupal installation. This takes a while. Consider using the --notify global option.

You are about to DROP all tables in your '<table_mane>' database. Do you want to continue? (y/n):

The important difference between these two messages is that the first one is printed to stderror while the second one is printed to stdout.

[greg-1-anderson]

It seems that we never switched drush_print to use fwrite instead of print. Making this adjustment allowed me to successfully install Drupal 7 using Drush 8.x with PHP 7.2.

I'll make a PR.

[greg-1-anderson]

@ryanaslett Please try #3353 and see if it also does the trick for you.