feat: add OnlyWarn flags in order to use pTrace during dev

gargantext.cabal

@@ -55,6 +55,7 @@ data-files:
     test-data/test_config.toml
     .clippy.dhall
 
+
 -- common options
 -- https://vrom911.github.io/blog/common-stanzas
 common defaults
@@ -100,6 +101,12 @@ flag no-phylo-debug-logs
   default: False
   manual: True
 
+
+Flag OnlyWarn
+  Description: More permissive rules during dev
+  Default:     False
+  Manual:      True
+
 library
   import:
     defaults
@@ -473,7 +480,14 @@ library
       Gargantext.Utils.Servant
       Gargantext.Utils.UTCTime
       Paths_gargantext
+  
+  -- By default every warning is an error 
   ghc-options: -Wall -Wincomplete-uni-patterns -Wincomplete-record-updates -Wmissing-signatures -Wunused-binds -Wunused-imports -Wunused-packages -Werror -freduction-depth=300 -fprint-potential-instances
+
+  -- But in dev warnings are not errors
+  if flag(OnlyWarn)
+    ghc-options: -Wwarn
+
   hs-source-dirs:
       src
   if flag(test-crypto)
@@ -572,6 +586,7 @@ library
     , patches-map ^>= 0.1.0.1
     , postgresql-simple >= 0.6.4 && <= 0.7.0.0
     , process ^>= 1.6.18.0
+    , pretty-simple
     , product-profunctors ^>= 0.11.0.3
     , protolude ^>= 0.3.3
     , quickcheck-instances ^>= 0.3.25.2