# Make petsc-slepc errors on centos 6.10
**URL:** https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960
**Category:** FreeFEM installation
**Created:** [May 3, 2021, 3:17am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960 "2021-05-03T03:17:51Z")
**Posts on this page:** 14
**Page:** 1
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 3, 2021, 3:17am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/1 "2021-05-03T03:17:51Z")
Hello,
I am trying to install FreeFem on Centos 6.10 following this guide Installation guide ([Installation guide](https://doc.freefem.org/introduction/installation.html)) section “Compilation on Ubuntu”.
I have found errors in step 6 with command “make petsc-slepc”:
I uploaded the configure.log file and ask for help.
Thank you.
[configure.log](https://community.freefem.org/uploads/short-url/wDIiKPgsg4iRbz1K0qNJNcM3uXP.log) (904.2 KB)
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [May 3, 2021, 6:35am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/2 "2021-05-03T06:35:23Z")
Thanks, I’ll forward this to the ParMmg developers. It looks like you are using a very old OS and a very old MPI implementation though, so it would be best to upgrade your system. In the meantime, you can simply remove all occurrences of `--download-parmmg` and `--with-parmmg-dir` from `3rdparty/ff-petsc/Makefile`.
Edit: just FYI, see [Undeclared MPI symbols · Issue #37 · MmgTools/ParMmg · GitHub](https://github.com/MmgTools/ParMmg/issues/37).
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 4, 2021, 3:51am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/3 "2021-05-04T03:51:03Z")
I simply remove --download-parmmg and --with-parmmg-dir occur in Makefile and it work well, thank you very much. but it occurs another error:
I uploaded the new configure.log file.
Thanks again.
[configure.log](https://community.freefem.org/uploads/short-url/ogQn03xF41B2dP9EAY4QTiQh73x.log) (3.0 MB)
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [May 4, 2021, 6:50am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/4 "2021-05-04T06:50:41Z")
Again, you have a very old Python which seems partially broken. You can just remove all `--download-slepc` occurences from `3rdparty/ff-petsc/Makefile`.
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 5, 2021, 9:12am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/5 "2021-05-05T09:12:16Z")
I update Python from 2.6.6 to 3.5.1, but make petsc-slepc still failed.
[configure.log](https://community.freefem.org/uploads/short-url/hVXra8siEPQSdjEyUKX8AJYSHFu.log) (2.3 MB)
thanks
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [May 5, 2021, 10:41am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/6 "2021-05-05T10:41:46Z")
Could you please upload `fr/externalpackages/git.slepc/installed-arch-linux2-c-opt/lib/slepc/conf/configure.log` as well?
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 5, 2021, 11:00am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/7 "2021-05-05T11:00:08Z")
[configure.log](https://community.freefem.org/uploads/short-url/7OpsoAk3Ahl5NTpNphtdpToFWt3.log) (4.3 KB)
ok, I upload it
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [May 5, 2021, 11:07am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/8 "2021-05-05T11:07:51Z")
Did you recompile from scratch when switching from Python 2.6.6 to Python 3.5.1?
I’m not sure you did, could you please `rm -rf /home/xlzheng/bin/FreeFem/ff-petsc` and `rm -rf 3rdparty/ff-petsc/petsc-3.15.0` and then `make petsc-slepc` again?
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 5, 2021, 12:16pm UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/9 "2021-05-05T12:16:51Z")
I repeat the progress following the Installation guide, but the warning “PETSc version 3.15 is newer than SLEPc version 3.14” still exist, same with the error “Unable to link with PETSc”.
I also try `rm -rf /home/xlzheng/bin/FreeFem/ff-petsc` and `rm -rf 3rdparty/ff-petsc/petsc-3.15.0` and then `make petsc-slepc` again. The error occurs again 😐
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 7, 2021, 9:24am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/10 "2021-05-07T09:24:57Z")
Hi Prj,
I did as you adviced, but the error in the fifth dialog box still exist. I don’t know why
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [May 7, 2021, 9:26am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/11 "2021-05-07T09:26:58Z")
Could you please upload the latest version of `3rdparty/ff-petsc/petsc-3.15.0/configure.log` and `3rdparty/ff-petsc/petsc-3.15.0/fr/externalpackages/git.slepc/installed-arch-linux2-c-opt/lib/slepc/conf/configure.log`?
I’ll forward this to the PETSc developers. Then, I’d suggest that you do as I proposed earlier to move forward, i.e., remove all occurences of `--download-slepc` in `3rdparty/ff-petsc/Makefile`.
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 7, 2021, 10:15am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/12 "2021-05-07T10:15:04Z")
[configure.log](https://community.freefem.org/uploads/short-url/udVXxmt1yMK3dEcXWpCmWWWJl3W.log) (1.3 MB)
[configure.log](https://community.freefem.org/uploads/short-url/kj4ykN5cvdM0zfxDR539UDH7V1s.log) (3.5 KB)
I upload the two configure.log in the order you mentioned
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [May 7, 2021, 10:21am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/13 "2021-05-07T10:21:42Z")
Thanks. In fact, I’m not sure removing `--download-slepc` will suffice, but you can try that. It would be much easier if you just use an up-to-date OS/compilation toolchain. GCC 4.8.5 is about 6-year old…
---
### Author:  [@xlzheng](https://community.freefem.org/u/xlzheng)
#### Post date: [May 7, 2021, 10:38am UTC](https://community.freefem.org/t/make-petsc-slepc-errors-on-centos-6-10/960/14 "2021-05-07T10:38:04Z")
Thank you, I‘ll try updating GCC