Opened 9 months ago

Last modified 7 months ago

#275 accepted Enhancement

FLEXTRA not compilable against eccodes

Reported by: hcpxvi Owned by: pesei
Priority: major Milestone: FLEXTRA 6
Component: FLEXTRA Version: FLEXTRA 5
Keywords: grib_api, GFS Cc:

Description (last modified by pesei)

FLEXTRA as supplied can not be compiled against eccodes. This is because when ECMWF retired libgrib_api and told everyone to move to eccodes, they also retired the Fortran 77 interface (which FLEXTRA uses). (This is not an issue for Flexpart which is in Fortran 9x, used the Fortran 9x interface to libgrib_api, and already compiles against eccodes.)

I am aware that the forthcoming FLEXTRA 6 will work with eccodes, so this problem should go away once FLEXTRA 6 is released --- I am happy to wait until that happens. I am putting in a ticket partly so that the enhancement request is on record and partly to document an approach to compiling FLEXTRA 5 with eccodes that didn't work for me, in case that information is of any help to the developers.

What I did was to delete the files gridcheck_gfs.f and readwind_gfs.f, then replace them with the versions at With the usual sort of changes to the makefile, FLEXTRA will compile and the FLEXTRA_GFS executable will run to the extent of telling you that you need to set up a pathnames file.

I next set up a pathnames file and an options directory for a short test run. I checked that the setup was correct by running a FLEXTRA executable linked against libgrib_api, obtaining the expected trajectory file. When I ran the executable compiled against eccodes with the same pathnames file and options directory it crashed with the error message

TEMP:    0.00000000    

A different test case that worked as expected with the executable linked against libgrib_api failed with the executable linked against eccodes, but with a different error:

 #### ERROR - TOO MANY STARTING POINTS        #### [...]

I set the priority on this ticket to "major". It could be regarded only as minor while it is still possible to keep a working copy of libgrib_api around. But it might escalate itself to critical once libgrib_api became difficult to use.

Change History (4)

comment:1 Changed 9 months ago by pesei

  • Description modified (diff)
  • Keywords grib_api GFS added
  • Milestone set to FLEXTRA 6
  • Owner set to pesei
  • Status changed from new to accepted

comment:2 Changed 9 months ago by pesei

  • Description modified (diff)

comment:3 Changed 9 months ago by pesei

As a clarification, obviously only gridcheck.f (ECMWF version) was updated in v5. After adapting the makefile, the ECMWF version does compile against eccodes.

Maybe the changes to gridcheck_gfs.f made by the Debian maintainer are insufficient. I'll check.

comment:4 Changed 7 months ago by hcpxvi

I note that, as of June, ECMWF have removed all trace of libgrib_api from their web site. So a new user downloading FLEXTRA and trying to get it to work with GFS winds can only do so if they already happen to have a working version of libgrib_api .

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