Installing the flatpak version of Octave is certainly very convenient. I have encountered some problems that some one might confirm or offer some work around.
I have been working on Linux Mint 18.3 (and in parallel to a Windows 10 PC). The latest compiled Octave package of 4.4.1 that I can find is 4.2.2. To obtain a more up to date version I have installed the flatpak version of 4.4.1. using a similar method to that described here.
I had problems installing forge packages such as nan and gsl in the flatpak version (messages received when I tried to install gsl is at the end of this email). I presume that the flatpak version can not access some required files.
I reinstalled the Octave 4.2.2 version and successfully reinstalled the required packages there. They now appear to be available to the flatpak version. At least the statistics package is working. I have not tried the gsl library. It is possible that the problems that caused it to fail may cause it when some gsl functions are called. At least I can use some Octave forge packages with the flatpak version and use the lder version when this fails. Does any one have any advice.
I have als installed flatpak emacs (version 26.1). Is there an easy way to use octave-mode on this flatpak version of emacs. It can read the same .emacs file as the standard version 25.3.2 version of emacs which dimplements octave -mode as expected. I have looked for a solution on the web and have failed to find one. Perhaps I have looked in the wrong placesll
########## Installin gsl on flatpak octave ###################
## Installed without on 4.2.2 immediately after trying 4.4.1 ###
################################################################
>> pkg install -forge gsl
configure: error: gslcblas library not found
checking for mkoctfile... /app/bin/mkoctfile-4.4.1
checking for octave... /app/bin/octave-4.4.1
checking for Octave's canonical_host_type... x86_64-pc-linux-gnu
checking for Octave's include directory... /app/include/octave-4.4.1/octave
checking whether the C++ compiler works... yes
checking for C++ compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C++ compiler... yes
checking whether g++ accepts -g... yes
checking how to run the C++ preprocessor... g++ -E
checking for grep that handles long lines and -e... /usr/bin/grep
checking for egrep... /usr/bin/grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking ov-scalar.h usability... yes
checking ov-scalar.h presence... yes
checking for ov-scalar.h... yes
checking for cos in -lm... yes
checking for cblas_dgemm in -lgslcblas... no
pkg: error running the configure script for gsl.
error: called from
configure_make at line 82 column 9
install at line 184 column 7
pkg at line 437 column 9