# Exact Cygwin package versions when building Julia

**URL:** <https://discourse.julialang.org/t/exact-cygwin-package-versions-when-building-julia/130162>\
**Category:** General Usage\
**Tags:** question\
**Created:** [June 24, 2025, 10:58am UTC](https://discourse.julialang.org/t/exact-cygwin-package-versions-when-building-julia/130162 "2025-06-24T10:58:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![gitboy16](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gitboy16/32/24906_2.png) [@gitboy16](https://discourse.julialang.org/u/gitboy16)\
**Post date:** [June 24, 2025, 10:58am UTC](https://discourse.julialang.org/t/exact-cygwin-package-versions-when-building-julia/130162/1 "2025-06-24T10:58:56Z")

</div>

Hi,  
I have moved to a new computer and struggling to build Julia from source on Windows with Cygwin.  
I am getting a message error saying:  
fatal error: mm\_malloc.h : No such file or directory.  
Is there a way to know what package versions are used to build the official Julia under Windows and Cygwin?  
I ambwondering if I am using the right gcc, make, fortran,..etc version.  
Thank you