# R: Sensitivity to C math library and mingw-w64 v12 - part 2

**URL:** <https://forum.devtalk.com/t/r-sensitivity-to-c-math-library-and-mingw-w64-v12-part-2/200117>\
**Category:** Backend Official News\
**Tags:** newsbot, library, r-lang, math, official-news\
**Created:** [22 May 2025 02:29 UTC](https://forum.devtalk.com/t/r-sensitivity-to-c-math-library-and-mingw-w64-v12-part-2/200117 "2025-05-22T02:29:13Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![NewsBot](https://forum.devtalk.com/user_avatar/forum.devtalk.com/newsbot/32/1114_2.png) [@NewsBot](https://forum.devtalk.com/u/NewsBot)\
**Post date:** [22 May 2025 02:29 UTC](https://forum.devtalk.com/t/r-sensitivity-to-c-math-library-and-mingw-w64-v12-part-2/200117/1 "2025-05-22T02:29:13Z")

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A new [R](https://devtalk.com/r) blog post/announcement has been posted!

> [@](#):
>
> C math library functions, such as exp or sin, are not guaranteed to be “precise”. The results might be slightly different on different platforms. A recent change in mingw-w64 v12, which is a core dependency of compilers we use on Windows (both GCC and LLVM), resulted in failures in about 20 CRAN packages. Rtools45 uses mingw-w64 v11, the same version as Rtools44, to allow time for resolving the issues. The change in mingw-w64 v12 switched about 90 math functions from internal implementations to UCRT, the Windows C runtime provided by Microsoft and shipped with the OS.

Get the full details here: [Sensitivity to C math library and mingw-w64 v12 - part 2 - The R Blog](https://blog.r-project.org/2025/05/21/sensitivity-to-c-math-library-and-mingw-w64-v12-part-2/)