date: Add option to use manual tz db

[Kaaml]

Specify library name and version: lib/1.0

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[danimtb]

Hi @Kaaml, thanks for your PR.

Could you explain a bit how does this work? I mean, setting this option to True in the recipe will lead to a different package, but, is this really true? Could you show how would a consumer of this recipe indicate the path to the manual DB? Thank you!

[Kaaml]

I detected other pull requests that are modifying date/all recipe:

• [date] Add tz recipe as a dependency #22294

This message is automatically generated by https://github.com/ericLemanissier/conan-center-conflicting-prs so don't hesitate to report issues/improvements there.

Hi @danimtb,

First of all, sorry for the long reply. Many users may have problem especially on windows when the date library checks for new version of IANA database and the end user doesn't have or want have 7zip in PATH variable. In my solution I put the flag to the library to block automatic download library. When this flag is set, users of the package have to remember to manually set location of IANA database.
date::set_install("/path/to/iana/database");
I saw few issues/PR for solving problem like this but all have all were more complicated and has dependency to other packages. This change can be replaced with more complex solution when will be ready.

[danimtb]

Hi @Kaaml and thanks for the reply.

I am not sure I totally understand the usage of the option. Do you mean that without this new option to set a manual path to the database, users have to do date::set_install("/path/to/iana/database"); in their project?

Also, as pointed out in my previous comment, setting manual_tz_db to True/False, will lead to different packages of date, but I am not sure if the binary packages are actually different... If they aren't, then this option will need to be excluded from the pacakge id

[Kaaml]

@danimtb

Hi @Kaaml and thanks for the reply.

I am not sure I totally understand the usage of the option. Do you mean that without this new option to set a manual path to the database, users have to do date::set_install("/path/to/iana/database"); in their project?

Currently when we use date::set_install("/path/to/iana/database"); the date library just changes the path to the IANA database. If there is no IANA database under this path, or if the version is older than on the IANA website, the library will download the new version and try to extract it and replace the original version.

If we use option manual_tz_db :

• autodownloading of IANA database will be disabled
• the date::set_install("/path/to/iana/database"); is required; Or you need to put IANA database in deafault path whic is declared in library ( usually something like this in Windows "c:\Users\username\Downloads" )

Also, as pointed out in my previous comment, setting manual_tz_db to True/False, will lead to different packages of date, but I am not sure if the binary packages are actually different... If they aren't, then this option will need to be excluded from the pacakge id

Yes, they are diffrent. Some functions has excluded some parts of code responsible for automatic download and checking for new version of IANA.

More details
In Date CMakeLists we have defined HAS_REMOTE_API=0 and AUTO_DOWNLOAD=0 variables when we define manual_tz_db. Next in
tz.cpp file we have some #IF based on previously defined in CMakeLists.txt. The line 3569 is most important for me because it's doing auto download when file doesn't exist and also updating to new version when file exist. It's worth to notice that if we set manual_tz_db the curl library is also redundatn and would not be linked.

[valgur]

Please add an options_description = { "use_system_tz_db": "...", ...} attribute to the recipe. Their meaning of these options and how they interact is a bit vague otherwise.

I would also maybe call the new option allow_tz_db_download instead.

[Kaaml]

Done

[conan-center-bot]

Conan v1 pipeline ❌

Failure in build 3 (de9ffc92c273054abdcaebf4dee5dba364b4b704):

• date/3.0.1:
  Didn't run or was cancelled before finishing

• date/3.0.0:
  Didn't run or was cancelled before finishing

• date/2.4.1:
  Error running command conan info date/2.4.1@#896b61eca1764c3c265f0a14f0def81c --json {jsonName} --dry-build -pr {profileName}:

  [settings]
  arch=x86_64
  build_type=Release
  compiler=gcc
  compiler.libcxx=libstdc++11
  compiler.version=5
  os=Linux
  [options]
  date:header_only=False
  date:shared=False
  
  ...
  ERROR: /home/conan/workspace/prod-v1/bsr/69828/bdaec/.conan/data/date/2.4.1/_/_/export/conanfile.py: Error while initializing options. option 'allow_tz_db_download' doesn't exist
  Possible options are ['shared', 'fPIC', 'header_only', 'use_system_tz_db', 'use_tz_db_in_dot', 'allow_tz_db_download ']
  

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^{Note: To save resources, CI tries to finish as soon as an error is found. For this reason you might find that not all the references have been launched or not all the configurations for a given reference. Also, take into account that we cannot guarantee the order of execution as it depends on CI workload and workers availability.}

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Conan v2 pipeline ❌

Note: Conan v2 builds are now mandatory. Please read our discussion about it.

The v2 pipeline failed. Please, review the errors and note this is required for pull requests to be merged. In case this recipe is still not ported to Conan 2.x, please, ping @conan-io/barbarians on the PR and we will help you.

Failure in build 3 (de9ffc92c273054abdcaebf4dee5dba364b4b704):

• date/3.0.1:
  Error running command conan export --name date --version 3.0.1 recipes/date/all/conanfile.py:

  ======== Exporting recipe to the cache ========
  ERROR: Error loading conanfile at '/home/conan/workspace/prod-v2_cci_PR-22690/recipes/date/all/conanfile.py': Error while initializing options. option 'allow_tz_db_download' doesn't exist
  Possible options are ['shared', 'fPIC', 'header_only', 'use_system_tz_db', 'use_tz_db_in_dot', 'allow_tz_db_download ']
  

• date/2.4.1:
  Error running command conan export --name date --version 2.4.1 recipes/date/all/conanfile.py:

  ======== Exporting recipe to the cache ========
  ERROR: Error loading conanfile at '/home/conan/workspace/prod-v2_cci_PR-22690/recipes/date/all/conanfile.py': Error while initializing options. option 'allow_tz_db_download' doesn't exist
  Possible options are ['shared', 'fPIC', 'header_only', 'use_system_tz_db', 'use_tz_db_in_dot', 'allow_tz_db_download ']
  

• date/3.0.0:
  Error running command conan export --name date --version 3.0.0 recipes/date/all/conanfile.py:

  ======== Exporting recipe to the cache ========
  ERROR: Error loading conanfile at '/home/conan/workspace/prod-v2_cci_PR-22690/recipes/date/all/conanfile.py': Error while initializing options. option 'allow_tz_db_download' doesn't exist
  Possible options are ['shared', 'fPIC', 'header_only', 'use_system_tz_db', 'use_tz_db_in_dot', 'allow_tz_db_download ']
  

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^{Note: To save resources, CI tries to finish as soon as an error is found. For this reason you might find that not all the references have been launched or not all the configurations for a given reference. Also, take into account that we cannot guarantee the order of execution as it depends on CI workload and workers availability.}