# Cannot install Fermi.jl due to version constraints
**URL:** https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157
**Category:** New to Julia
**Tags:** quantum, cuda, versions
**Created:** [June 24, 2025, 9:03am UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157 "2025-06-24T09:03:43Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Uranium238](https://discourse.julialang.org/u/Uranium238)
#### Post date: [June 24, 2025, 9:03am UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157/1 "2025-06-24T09:03:43Z")
I am trying to install Fermi.jl on the newest stable release of Julia. On doing a fresh install and activating a completely new environment, when I do `] add Fermi`, I am met with the following error message :
```julia
(@v1.11) pkg> activate .
Activating new project at `~/swapan-lab/polariton`
(polariton) pkg> add Fermi
Resolving package versions...
ERROR: Unsatisfiable requirements detected for package GPUCompiler [61eb1bfa]:
GPUCompiler [61eb1bfa] log:
├─possible versions are: 0.1.0 - 1.5.3 or uninstalled
├─restricted by julia compatibility requirements to versions: 0.23.0 - 1.5.3 or uninstalled
└─restricted by compatibility requirements with CUDA [052768ef] to versions: [0.12.0 - 0.12.9, 0.13.3 - 0.17.3] — no versions left
└─CUDA [052768ef] log:
├─possible versions are: 0.1.0 - 5.8.2 or uninstalled
├─restricted by julia compatibility requirements to versions: [2.3.0, 2.5.0 - 5.8.2] or uninstalled
├─restricted by compatibility requirements with PrettyTables [08abe8d2] to versions: 0.1.0 - 4.4.2 or uninstalled, leaving only versions: [2.3.0, 2.5.0 - 4.4.2] or uninstalled
│ └─PrettyTables [08abe8d2] log:
│ ├─possible versions are: 0.1.0 - 2.4.0 or uninstalled
│ └─restricted by compatibility requirements with Fermi [9237668d] to versions: [0.9.1 - 0.11.1, 1.0.0 - 1.3.1]
│ └─Fermi [9237668d] log:
│ ├─possible versions are: 0.0.1 - 0.4.0 or uninstalled
│ └─restricted to versions * by an explicit requirement, leaving only versions: 0.0.1 - 0.4.0
├─restricted by compatibility requirements with TensorOperations [6aa20fa7] to versions: 0.1.0 - 3.13.1, leaving only versions: [2.3.0, 2.5.0 - 3.13.1]
│ └─TensorOperations [6aa20fa7] log:
│ ├─possible versions are: 0.6.1 - 5.2.0 or uninstalled
│ └─restricted by compatibility requirements with Fermi [9237668d] to versions: 3.0.0 - 3.2.5
│ └─Fermi [9237668d] log: see above
└─restricted by compatibility requirements with LLVM [929cbde3] to versions: 3.3.3 - 5.8.2 or uninstalled, leaving only versions: 3.3.3 - 3.13.1
└─LLVM [929cbde3] log:
├─possible versions are: 0.9.0 - 9.4.1 or uninstalled
└─restricted by julia compatibility requirements to versions: 4.0.0 - 9.4.1 or uninstalled
```
I am unsure how to resolve this issue, any help is highly appreciated.
---
### Author:  [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)
#### Post date: [June 24, 2025, 1:52pm UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157/2 "2025-06-24T13:52:52Z")
It looks like Fermi hasn’t had a release in ~3 years and asusch is forcing some fairly old package versions. Does `]add Fermi#master` work?
---
### Author:  [@Uranium238](https://discourse.julialang.org/u/Uranium238)
#### Post date: [June 24, 2025, 6:38pm UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157/3 "2025-06-24T18:38:37Z")
> [@Oscar\_Smith](#):
>
> Does `]add Fermi#master` work?
Yes it does work, thank you so much!
It does give a few warnings during precompilation though :
```julia
(rough) pkg> add Fermi#master
Updating git-repo `https://github.com/FermiQC/Fermi.jl.git`
Resolving package versions...
No Changes to `~/rough/Project.toml`
No Changes to `~/rough/Manifest.toml`
Precompiling packages finished.
2 dependencies successfully precompiled in 302 seconds. 114 already precompiled.
1 dependency had output during precompilation:
┌ Fermi
│ WARNING: using Molecules.Molecule in module HartreeFock conflicts with an existing identifier.
│ WARNING: using Molecules.Molecule in module MollerPlesset conflicts with an existing identifier.
│ WARNING: method definition for RCCSD at /home/anik/.julia/packages/Fermi/12eZN/src/Methods/CoupledCluster/RCCSD/RCCSDa.jl:37 declares type variable T2 but does not use it.
│ WARNING: using Molecules.Molecule in module CoupledCluster conflicts with an existing identifier.
```
---
### Author:  [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)
#### Post date: [June 26, 2025, 6:04pm UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157/4 "2025-06-26T18:04:28Z")
A new version of Fermi was just tagged, so the workaround should no longer be necessary.
---
### Author:  [@Uranium238](https://discourse.julialang.org/u/Uranium238)
#### Post date: [July 3, 2025, 6:03am UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157/5 "2025-07-03T06:03:00Z")
Yes, at least for Julia 1.10.9 , it is installing naturally using the default `add Fermi` command.