[flake] fixes to cabal freeze so that nix shell works

README.md

@@ -481,6 +481,23 @@ golden reference). To do so, it's enough to run the testsuite passing the `--acc
 cabal v2-test garg-test-tasty --test-show-details=streaming --flags 'test-crypto no-phylo-debug-logs' --test-option=--pattern='/Phylo/' --test-option=--accept"
 ```
 
+# Nix flake
+
+With `flake.nix` one can run server like this:
+```shell
+nix run .#gargantext:exe:gargantext
+```
+The tests can be run with:
+```shell
+nix run .#gargantext:test:garg-test-tasty
+nix run .#gargantext:test:garg-test-hspec
+```
+
+For dev shell:
+```shell
+nix -L develop
+```
+
 # Async workers <a name="async-workers"></a>
 
 ## Steps to configure the worker

cabal.project.freeze

@@ -236,7 +236,7 @@ constraints: any.Boolean ==0.2.4,
              hedis -dev,
              any.hlcm ==0.2.2,
              any.hmatrix ==0.20.2,
-             hmatrix -disable-default-paths -no-random_r -openblas,
+             hmatrix -disable-default-paths -no-random_r +openblas,
              any.hmatrix-gsl-stats ==0.4.1.8,
              hmatrix-gsl-stats -onlygsl,
              any.hourglass ==0.2.12,