let's try without the foreign-library trash..

hstherac25.cabal

@@ -59,23 +59,22 @@ common windowsflags-lib
 common windowsflags-exe
     ghc-options: -Wall -O2 -threaded -with-rtsopts=-N
 -- don't forget to set those in hs_init when loading
-foreign-library hstherac25
-    type: native-shared
-    if os(windows)
-        import: windowsflags-lib
-        options: standalone
-    else
-       import: linuxflags
-    -- Directories containing source files.
-    hs-source-dirs:   src-lib
-    -- Base language which the package is written in.
-    default-language: GHC2021
-    build-depends:    base >=4.15.0.0,
-                      containers >= 0.6.7,
-                      lens >= 5.2.3,
-                      random >= 1.2.1.1,
-                      stm
-    exposed-modules: HsTherac25
+--foreign-library hstherac25
+--    type: native-shared
+--    if os(windows)
+--        import: windowsflags-lib
+--        options: standalone
+--    else
+--       import: linuxflags
+--    -- Directories containing source files.
+--    hs-source-dirs:   src-lib
+--    -- Base language which the package is written in.
+--    default-language: GHC2021
+--    build-depends:    base >=4.15.0.0,
+--                      containers >= 0.6.7,
+--                      lens >= 5.2.3,
+--                      random >= 1.2.1.1,
+--                      stm
 --    other-modules:  HsTherac25
 library
     -- Import common warning flags.