# CCTM (CMAQv5.5) compile error

**URL:** <https://forum.cmascenter.org/t/cctm-cmaqv5-5-compile-error/5642>\
**Category:** Compiling\
**Tags:** cmaq\
**Created:** [March 4, 2025, 1:31am UTC](https://forum.cmascenter.org/t/cctm-cmaqv5-5-compile-error/5642 "2025-03-04T01:31:25Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![atmos007](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@atmos007](https://forum.cmascenter.org/u/atmos007)\
**Post date:** [March 4, 2025, 1:31am UTC](https://forum.cmascenter.org/t/cctm-cmaqv5-5-compile-error/5642/1 "2025-03-04T01:31:25Z")

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Hi, All. An error, " Can’t find an intrinsic module named ‘ieee\_arithmetic’",appeared during compiling CCTM with CMAQv5.5. And the gfortran version I used is 4.8.5. What could be the reason? The log file is attached below:  
[build\_cctm\_ddm.log.txt](https://forum.cmascenter.org/uploads/short-url/sZmRFXms1juwgE430W9ZReIcmWF.txt) (419.2 KB)

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**Author:** ![hogrefe.christian](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hogrefe.christian](https://forum.cmascenter.org/u/hogrefe.christian)\
**Post date:** [March 4, 2025, 12:30pm UTC](https://forum.cmascenter.org/t/cctm-cmaqv5-5-compile-error/5642/2 "2025-03-04T12:30:54Z")

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Based on this [stackoverflow thread](https://stackoverflow.com/questions/30747019/ieee-arithmetic-intrinsic-module-in-gfortran) and its link to [gfortran documentation](https://gcc.gnu.org/gcc-5/changes.html), the ieee\_arithmetic module is available for gfortran version 5 or higher.

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**Author:** ![atmos007](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@atmos007](https://forum.cmascenter.org/u/atmos007)\
**Post date:** [March 5, 2025, 3:19am UTC](https://forum.cmascenter.org/t/cctm-cmaqv5-5-compile-error/5642/3 "2025-03-05T03:19:06Z")

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Hi, Christian. You are right, and thank you so much for your suggestion. I have used an older version that include bugfixes for CMAQ DDM-3D. But I have a question: if I update gfortran, will I need to reinstall netcdf and ioapi which are based on version 4.8.5?

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**Author:** ![hogrefe.christian](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hogrefe.christian](https://forum.cmascenter.org/u/hogrefe.christian)\
**Post date:** [March 5, 2025, 12:21pm UTC](https://forum.cmascenter.org/t/cctm-cmaqv5-5-compile-error/5642/4 "2025-03-05T12:21:11Z")

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Yes. If you update your compiler version, you will have to reinstall the netcdf and ioapi libraries before recompiling CMAQ.