# Issues building CRTM 2.4.0
**URL:** https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705
**Category:** CRTM
**Created:** [September 18, 2025, 8:57pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705 "2025-09-18T20:57:11Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@joehellmersNOAA](https://forums.jcsda.org/u/joehellmersNOAA)
#### Post date: [September 18, 2025, 8:57pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/1 "2025-09-18T20:57:11Z")
Hello,
I’m trying to build CRTM, but the configure command gives a CRTM\_Module.F90 source file not found.
What I’m doing specifically which I think is following the directions exactly ..
```auto
. configuration/gfortran-debug.setup
. ./Set_CRTM_Environment.sh
cd src
/make realclean
make
cd Build/
./configure --prefix=${PWD}
configure: error: cannot find sources (libsrc/CRTM_Module.F90) in . or ..
pwd
home_folder/environment/github/JCSDA/crtm/src/Build
```
Thanks for the help.
Joe
---
### Author:  [@BenjaminTJohnson](https://forums.jcsda.org/u/BenjaminTJohnson)
#### Post date: [September 18, 2025, 9:08pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/2 "2025-09-18T21:08:17Z")
Hi;
which version and where are you getting it from?
Also which compiler version are you trying to use?
---
### Author:  [@joehellmersNOAA](https://forums.jcsda.org/u/joehellmersNOAA)
#### Post date: [September 18, 2025, 9:12pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/3 "2025-09-18T21:12:36Z")
I’m specifying the 2.4.0 branch.
`git clone --branch=v2.4.0 https://github.com/JCSDA/crtm`
I’ve tried gfortran 11.5 on AL2023 and 14.2.0 on Ubuntu 24.04.2
---
### Author:  [@BenjaminTJohnson](https://forums.jcsda.org/u/BenjaminTJohnson)
#### Post date: [September 18, 2025, 9:24pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/4 "2025-09-18T21:24:48Z")
If you’re starting a new application, or trying to interface something new with CRTM we highly recommend that use version three
[https://github.com/JCSDA/CRTMv3](https://github.com/JCSDA/CRTMv3)
If you still need to use version 2.4.0, Let me know and then we can dig a little bit deeper into what’s going on.
---
### Author:  [@joehellmersNOAA](https://forums.jcsda.org/u/joehellmersNOAA)
#### Post date: [September 19, 2025, 12:42pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/5 "2025-09-19T12:42:45Z")
Thanks for the help Benjamin. I’m not sure trying to use v3.x.x is acceptable to the folks I’m working with. The task I have is to use f2py to make an interface for Python and thus far I’ve heard that they want 2.4.0, but I can check if that would be OK.
Are there other things I could try? Different OSes, Fortran versions, or even different Fortran compilers?
I will go ahead and try out 3.x.x just in case they don’t really care.
---
### Author:  [@BenjaminTJohnson](https://forums.jcsda.org/u/BenjaminTJohnson)
#### Post date: [September 19, 2025, 1:10pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/6 "2025-09-19T13:10:29Z")
A few comments:
There’s already a pycrtm: [https://github.com/JCSDA/pycrtm](https://github.com/JCSDA/pycrtm)
If you’re helping EMC, you’ll want to use: release/REL-2.4.0\_emc branch (I recommend this anyway).
If you’re just required to use 2.4.x, I recommend using the branch: release/crtm\_jedi\_v2.4.1
Otherwise, CRTMv3 is superior.
To address your actual error: what’s happening is that you might’ve forgotten to run make in the src/ directory first, which links the various files into the libsrc directory.
This can also happen if the Get\_CRTM\_Binary\_Files.sh didn’t work. Strongly recommend using one of the above branches, and reading the installation directions (i.e., use CMake instead of configure).
---
### Author:  [@joehellmersNOAA](https://forums.jcsda.org/u/joehellmersNOAA)
#### Post date: [September 19, 2025, 3:04pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/7 "2025-09-19T15:04:50Z")
Thanks. I was able to get the EMC branch working. I did have to get ecbuild in my path, so maybe that was my problem all along.
I think I did run make in the /src branch, but their might have been errors.
I will go ahead and try 3.1.2 just for fun, and look into pycrtm.
---
### Author:  [@antoniosandroni](https://forums.jcsda.org/u/antoniosandroni)
#### Post date: [October 29, 2025, 6:19pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/8 "2025-10-29T18:19:20Z")
Hi, I am kinda new to CRTM.
I just wanna ask why in the v2.4.0 there is a src/Build folder and in the v3 version it is not present.
When I compile the v2.4.0 using the singularity container running “ecbuild ..” in /crtm/build, do I need to run make inside /crtm/src/Build?
Thanks
---
### Author:  [@BenjaminTJohnson](https://forums.jcsda.org/u/BenjaminTJohnson)
#### Post date: [October 29, 2025, 6:31pm UTC](https://forums.jcsda.org/t/issues-building-crtm-2-4-0/705/9 "2025-10-29T18:31:26Z")
Not necessary when using ecbuild or cmake.
src/Build is for backwards support for autotools builds.
We fully recommend using CRTMv3 in general.