Upgrade fortran compiler on Windows

[metab0t]

Comment:

Since scipy has been successfully built with flang on windows, is it possible to upgrade the fortran compiler on windows from flang 5 to flang 17?

[h-vetinari]

Currently planning / hoping to do this with flang 18 early next year

[jorisv]

Hello,

Any news on this issue ?
Right now trying to install llvm-openmp with last ipopt version fail on Windows because of conflict with openmp version needed by flang 5.

conda create -n test ipopt=3.14.16 llvm-openmp

LibMambaUnsatisfiableError: Encountered problems while solving:
  - package ipopt-3.14.16-h394f428_0 requires libflang >=5.0.0,<6.0.0.a0, but none of the providers can be installed

Could not solve for environment specs
The following packages are incompatible
├─ ipopt 3.14.16**  is not installable because it requires
│  ├─ libflang >=5.0.0,<6.0.0.a0  with the potential options
│  │  ├─ libflang 5.0.0 would require
│  │  │  └─ openmp 5.0.0 , which can be installed;
│  │  ├─ libflang 5.0.0 would require
│  │  │  └─ vc 14 , which can be installed;
│  │  └─ libflang 5.0.0 would require
│  │     ├─ openmp 5.0.0 , which can be installed;
│  │     └─ vc 14 , which can be installed;
│  ├─ mumps-seq [>=5.6.2,<5.6.3.0a0 |>=5.7.0,<5.7.1.0a0 |>=5.7.1,<5.7.2.0a0 |>=5.7.2,<5.7.3.0a0 |>=5.7.3,<5.7.4.0a0 ] but there are no viable options
│  │  ├─ mumps-seq [5.6.2|5.7.0|5.7.1] would require
│  │  │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
│  │  └─ mumps-seq [5.7.2|5.7.3] would require
│  │     ├─ libflang >=5.0.0,<6.0.0.a0 , which can be installed (as previously explained);
│  │     └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
│  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
└─ llvm-openmp is not installable because there are no viable options
   ├─ llvm-openmp 12.0.0 would require
   │  └─ openmp 12.0.0|12.0.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 10.0.0 would require
   │  └─ openmp 10.0.0|10.0.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 10.0.1 would require
   │  └─ openmp 10.0.1|10.0.1.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 11.0.0 would require
   │  └─ openmp 11.0.0|11.0.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 11.0.1 would require
   │  └─ openmp 11.0.1|11.0.1.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 11.1.0 would require
   │  └─ openmp 11.1.0|11.1.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 12.0.1 would require
   │  └─ openmp 12.0.1|12.0.1.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 13.0.1 would require
   │  └─ openmp 13.0.1|13.0.1.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 14.0.0 would require
   │  └─ openmp 14.0.0|14.0.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 14.0.2 would require
   │  └─ openmp 14.0.2|14.0.2.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 14.0.3 would require
   │  └─ openmp 14.0.3|14.0.3.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 14.0.4 would require
   │  └─ openmp 14.0.4|14.0.4.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 14.0.6 would require
   │  ├─ openmp 14.0.6|14.0.6.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 15.0.4 would require
   │  ├─ openmp 15.0.4|15.0.4.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 15.0.5 would require
   │  ├─ openmp 15.0.5|15.0.5.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 8.0.0 would require
   │  └─ openmp 8.0.0|8.0.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 8.0.1 would require
   │  └─ openmp 8.0.1|8.0.1.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 9.0.0 would require
   │  └─ openmp 9.0.0|9.0.0.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 9.0.1 would require
   │  └─ openmp 9.0.1|9.0.1.* , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 15.0.6 would require
   │  ├─ openmp 15.0.6|15.0.6.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 15.0.7 would require
   │  ├─ openmp 15.0.7|15.0.7.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.0 would require
   │  ├─ openmp 16.0.0|16.0.0.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.1 would require
   │  ├─ openmp 16.0.1|16.0.1.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.2 would require
   │  ├─ openmp 16.0.2|16.0.2.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.3 would require
   │  ├─ openmp 16.0.3|16.0.3.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.4 would require
   │  ├─ openmp 16.0.4|16.0.4.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.5 would require
   │  ├─ openmp 16.0.5|16.0.5.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 16.0.6 would require
   │  ├─ openmp 16.0.6|16.0.6.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 17.0.2 would require
   │  ├─ openmp 17.0.2|17.0.2.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 17.0.3 would require
   │  ├─ openmp 17.0.3|17.0.3.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 17.0.4 would require
   │  ├─ openmp 17.0.4|17.0.4.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 17.0.5 would require
   │  ├─ openmp 17.0.5|17.0.5.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 17.0.6 would require
   │  ├─ openmp 17.0.6|17.0.6.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.1 would require
   │  ├─ openmp 18.1.1|18.1.1.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.2 would require
   │  ├─ openmp 18.1.2|18.1.2.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.3 would require
   │  ├─ openmp 18.1.3|18.1.3.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.4 would require
   │  ├─ openmp 18.1.4|18.1.4.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.5 would require
   │  ├─ openmp 18.1.5|18.1.5.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.6 would require
   │  ├─ openmp 18.1.6|18.1.6.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.7 would require
   │  ├─ openmp 18.1.7|18.1.7.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   ├─ llvm-openmp 18.1.8 would require
   │  ├─ openmp 18.1.8|18.1.8.* , which conflicts with any installable versions previously reported;
   │  └─ vc >=14.2,<15 , which conflicts with any installable versions previously reported;
   └─ llvm-openmp 14.0.6 would require
      └─ openmp 14.0.6|14.0.6.* , which conflicts with any installable versions previously reported.

[h-vetinari]

We're not far from unblocking the whole llvm 19 stack (I had prepared everything during the RCs and before, but got some requested changes after release that I need to get to but don't have time for at the moment, as I'm travelling). Should be a matter of days or weeks