When install fails: Fatal error: Call to undefined function theme() in install.core.inc on line 954 [#2091501]

Updated: Comment #N

Problem/Motivation

The installation process sometimes fails with the error message

"Fatal error: Call to undefined function theme() in xxx/core/includes/install.core.inc on line 1009."

The install_drupal function tries to catch exceptions thrown by install_begin_request using install_display_output, however install_display_output returns a themed page, and the theme system is only loaded during install_begin_request. Therefore, if an exception is thrown too soon, the user will get the above error message (triggered on the penultimate line of install_display_output).

This was spotted while working on #2110863: Support open_basedir amoung other instances.

Proposed resolution

Check the theming system is ready before using it and/or have another error handler ready to handle an error thrown by the theming system.

Remaining tasks

Decide on approach
Write patch

User interface changes

None

API changes

None

Comment	File	Size	Author
#4	2091501-4-undefined-function-theme.patch	850 bytes	ianthomas_uk
#4
#4	2091501-4-example-exception-do-not-test.diff	541 bytes	ianthomas_uk
#4

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Comments

Comment #1

Alan D. CreditAttribution: Alan D. commented 12 October 2013 at 00:08

I was easily able to replicate with an existing settings.php file that contained a reference to an existing database that was empty.

Removing the file allowed installation to get to the first page of the install successfully.
Removing the $databases['default']['default'] but keeping the rest of the settings.php file as is, gave an "Drupal already installed" message (file was from a post Drupal 8 alpha 2 install from memory).

Comment #2

ianthomas_uk

he/him

English

Brighton, UK

CreditAttribution: ianthomas_uk commented 10 December 2013 at 00:11

Issue summary:	View changes
Priority:	Normal	» Major
Related issues:		+#2110863: Support open_basedir

Updating summary using the template and a more technical description of what is happening.

Original summary

When the install of Drupal 8 fails it (might) fail(s) with the message:

Fatal error: Call to undefined function theme() in drupal\core\includes\install.core.inc on line 954

There are other issues that do mention this error message, but they focus on eliminating a specific case that lead to the install procedure to fail. This issue should make sure that the install fails with a proper message to the user (the message that probably was themed when this error occurs) not with this fatal.

Note: in my case it was an already existing settings.php, a situation that before, IIRC, was handled with a correct message.

Comment #3

Alan D. CreditAttribution: Alan D. commented 10 December 2013 at 02:56

From #2110863-9: Support open_basedir

If you enable open_basedir, this patch gets the install process past the initial open_basedir errors, but after the database is created, before it starts the main install it now throws "Fatal error: Call to undefined function theme() in xxx/core/includes/install.core.inc on line 992."

Note that in my case open_basedir was not set. There may be multiple entry points to getting this same error.

Comment #4

ianthomas_uk

he/him

English

Brighton, UK

CreditAttribution: ianthomas_uk commented 11 December 2013 at 23:15

Status:

Active

» Needs review

File	Size
2091501-4-example-exception-do-not-test.diff	541 bytes

2091501-4-undefined-function-theme.patch	850 bytes

Here's a patch that will just rethrow the exception instead of attempting to display a nicely themed page if that's not going to possible.

Instead of

"Fatal error: Call to undefined function theme() in xxx/core/includes/install.core.inc on line 1009."

the user will see

Fatal error: Uncaught exception 'Exception' with message '[exception message]' in xxx/core/includes/install.core.inc:257 Stack trace: #0 xxx/core/includes/install.core.inc(92): install_begin_request(Array) #1 xxx/core/install.php(50): install_drupal() #2 {main} thrown in xxx/core/includes/install.core.inc on line 257

Hopefully the exception message will help them solve their problem, but at the very least it will lead them to a better place to start debugging. I've also uploaded a patch to throw an exception that would trigger this problem, for review purposes.