# What's the difference between this PROJ\_DATA\_SUBDIR and DATADIR when cmake is configuring the proj library?

**URL:** <https://discourse.cmake.org/t/whats-the-difference-between-this-proj-data-subdir-and-datadir-when-cmake-is-configuring-the-proj-library/2353>\
**Category:** Code\
**Created:** [December 12, 2020, 8:04am UTC](https://discourse.cmake.org/t/whats-the-difference-between-this-proj-data-subdir-and-datadir-when-cmake-is-configuring-the-proj-library/2353 "2020-12-12T08:04:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mirro187](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mirro187](https://discourse.cmake.org/u/mirro187)\
**Post date:** [December 12, 2020, 8:04am UTC](https://discourse.cmake.org/t/whats-the-difference-between-this-proj-data-subdir-and-datadir-when-cmake-is-configuring-the-proj-library/2353/1 "2020-12-12T08:04:18Z")

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![QQ图片20201212160226](https://discourse.cmake.org/uploads/default/original/2X/e/eff9280179fa1c01119379524b7f95a54428e2ca.jpeg)

> **[OSGeo/PROJ](https://github.com/OSGeo/PROJ)**
>
> PROJ - Cartographic Projections and Coordinate Transformations Library - OSGeo/PROJ

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**Author:** ![ben.boeckel](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)\
**Post date:** [January 4, 2021, 8:08pm UTC](https://discourse.cmake.org/t/whats-the-difference-between-this-proj-data-subdir-and-datadir-when-cmake-is-configuring-the-proj-library/2353/2 "2021-01-04T20:08:29Z")

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Depends on where they come from. The unadorned ones probably come from an embedded third-party library or some other generic code. I would ask proj if they could resolve the confusion by eliminating some variables from appearing in the cache at all.