can't modify frozen NilClass

[tpitale]

Calling empty? on an has n association. Ruby 2.2.0, worked previous versions of ruby.

from bundle/ruby/2.2.0/gems/dm-types-1.2.2/lib/dm-types/support/dirty_minder.rb:144:in `track'
from bundle/ruby/2.2.0/gems/dm-types-1.2.2/lib/dm-types/support/dirty_minder.rb:161:in `hook_value'
from bundle/ruby/2.2.0/gems/dm-types-1.2.2/lib/dm-types/support/dirty_minder.rb:151:in `set!'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/model.rb:607:in `block (2 levels) in load'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/model.rb:598:in `each'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/model.rb:598:in `block in load'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/model.rb:577:in `map'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/model.rb:577:in `load'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/repository.rb:162:in `read'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/collection.rb:1118:in `lazy_load'
from bundle/ruby/2.2.0/gems/dm-core-1.2.1/lib/dm-core/support/lazy_array.rb:87:in `empty?'
from (irb):2
from bundle/ruby/2.2.0/gems/railties-4.2.0/lib/rails/commands/console.rb:110:in `start'
from bundle/ruby/2.2.0/gems/railties-4.2.0/lib/rails/commands/console.rb:9:in `start'
from bundle/ruby/2.2.0/gems/railties-4.2.0/lib/rails/commands/commands_tasks.rb:68:in `console'
from bundle/ruby/2.2.0/gems/railties-4.2.0/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from bundle/ruby/2.2.0/gems/railties-4.2.0/lib/rails/commands.rb:17:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'irb(main):003:0> r.extract_logs.empty?

[tpitale]

Subsequent calls to exactly the same method work. Always fails the first time.

[tpitale]

This may be a dm-core issue, and only happens to manifest through dm-types because of the DirtyMinder module misdirection.

[tpitale]

This appears to be related to #71. Closing.

[tpitale]

Loading a collection at all, for the first time (as empty? evidently does in dm) where one of the properties is Json, Hash, or Array (the classes extended by hooks for dirtiness tracking) leads to this error. No other collection loading fails in this way. Pretty sure that makes it a dm-types issue.

[tpitale]

This is fixed by PR #50. But, despite it saying in the release from github that v1.2.2 v1.2.2...master has that PR included, looking at the code for the gem release 1.2.2 it does not have the code from PR #50.

[robclancy]

This issue has made me regret use datamapper at all :/

[gregory]

same here. that's bad.

[julienma]

Well, same issue.
Had to fork v1.2.2 and cherry pick the 3 commits from #50.

Now, I just have to add this to my Gemfile:

gem 'dm-types',
  :git => 'git://github.com/julienma/dm-types.git',
  :branch => 'gem-v1.2.2-with-frozen-nilclass-fix'

[ZeroChaos-]

kinda looks like this still isn't fixed, is this ever going to be fixed?

2016-06-30T14:17:40.172+0000 ERROR pwnscan#9456: Generic Error: can't
modify frozen NilClass
["/var/lib/gems/2.3.0/gems/dm-types-1.2.2/lib/dm-types/support/dirty_minder.rb:144:in
`track'",
"/var/lib/gems/2.3.0/gems/dm-types-1.2.2/lib/dm-types/support/dirty_minder.rb:161:in
`hook_value'",
"/var/lib/gems/2.3.0/gems/dm-types-1.2.2/lib/dm-types/support/dirty_minder.rb:151:in
`set!'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/resource.rb:880:in
`block in eager_load'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/resource.rb:880:in
`each'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/resource.rb:880:in
`eager_load'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/resource.rb:865:in
`lazy_load'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/property.rb:664:in
`lazy_load'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/resource/persistence_state/persisted.rb:23:in
`lazy_load'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/resource/persistence_state/persisted.rb:8:in
`get'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/model/property.rb:209:in
`attributes_meta'",
"/opt/pwnix/pwnscan/lib/pwnscan/helpers/host_update_helper.rb:21:in
`initialize'",
"/opt/pwnix/pwnscan/lib/pwnscan/models/network_host.rb:252:in `new'",
"/opt/pwnix/pwnscan/lib/pwnscan/models/network_host.rb:252:in
`update_from_parsed_hash'",
"/opt/pwnix/pwnscan/lib/pwnscan/models/network_host.rb:265:in
`mark_offline'",
"/opt/pwnix/pwnscan/lib/pwnscan/models/network_host.rb:97:in `block in
deduplicate'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/collection.rb:508:in
`block in each'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/support/lazy_array.rb:411:in
`block in each'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/support/lazy_array.rb:411:in
`each'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/support/lazy_array.rb:411:in
`each'",
"/var/lib/gems/2.3.0/gems/dm-core-1.2.1/lib/dm-core/collection.rb:505:in

[tpitale]

DM is mostly unmaintained. So, no, probably not getting fixed.

[jcran]

Ran into this as well, accelerated a project's move off datamapper.

[joshleblanc]

This can be avoided by turning off lazy loading for the property.

property :some_json, Json, lazy: false

Obviously, you lose the benefits of lazy loading.