diff --git a/Cargo.lock b/Cargo.lock
index dc9e364812..d2babf3e7b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3351,6 +3351,7 @@ dependencies = [
  "roc_parse",
  "roc_problem",
  "roc_region",
+ "roc_reporting",
  "roc_target",
  "roc_types",
  "roc_unify",
@@ -3519,6 +3520,7 @@ dependencies = [
  "roc_module",
  "roc_parse",
  "roc_region",
+ "roc_reporting",
  "roc_target",
  "roc_types",
  "snafu",
diff --git a/ast/Cargo.toml b/ast/Cargo.toml
index 86d203cee4..d1384b96ee 100644
--- a/ast/Cargo.toml
+++ b/ast/Cargo.toml
@@ -19,6 +19,7 @@ roc_unify = { path = "../compiler/unify"}
 roc_load = { path = "../compiler/load" }
 roc_target = { path = "../compiler/roc_target" }
 roc_error_macros = { path = "../error_macros" }
+roc_reporting = { path = "../reporting" }
 arrayvec = "0.7.2"
 bumpalo = { version = "3.8.0", features = ["collections"] }
 page_size = "0.4.2"
diff --git a/ast/src/module.rs b/ast/src/module.rs
index 55b324b35d..769df5d162 100644
--- a/ast/src/module.rs
+++ b/ast/src/module.rs
@@ -19,6 +19,7 @@ pub fn load_module(src_file: &Path) -> LoadedModule {
         }),
         subs_by_module,
         TargetInfo::default_x86_64(),
+        roc_reporting::report::RenderTarget::ColorTerminal,
     );
 
     match loaded {
diff --git a/ast/src/solve_type.rs b/ast/src/solve_type.rs
index dc2e53f3a8..f15b128827 100644
--- a/ast/src/solve_type.rs
+++ b/ast/src/solve_type.rs
@@ -227,12 +227,16 @@ fn solve<'a>(
             );
 
             match unify(subs, actual, expected, Mode::EQ) {
-                Success(vars) => {
+                Success {
+                    vars,
+                    must_implement_ability: _,
+                } => {
+                    // TODO(abilities) record deferred ability checks
                     introduce(subs, rank, pools, &vars);
 
                     state
                 }
-                Failure(vars, actual_type, expected_type) => {
+                Failure(vars, actual_type, expected_type, _bad_impl) => {
                     introduce(subs, rank, pools, &vars);
 
                     let problem = TypeError::BadExpr(
@@ -267,7 +271,7 @@ fn solve<'a>(
         //
         //                    state
         //                }
-        //                Failure(vars, _actual_type, _expected_type) => {
+        //                Failure(vars, _actual_type, _expected_type, _bad_impl) => {
         //                    introduce(subs, rank, pools, &vars);
         //
         //                    // ERROR NOT REPORTED
@@ -320,13 +324,17 @@ fn solve<'a>(
                     );
 
                     match unify(subs, actual, expected, Mode::EQ) {
-                        Success(vars) => {
+                        Success {
+                            vars,
+                            must_implement_ability: _,
+                        } => {
+                            // TODO(abilities) record deferred ability checks
                             introduce(subs, rank, pools, &vars);
 
                             state
                         }
 
-                        Failure(vars, actual_type, expected_type) => {
+                        Failure(vars, actual_type, expected_type, _bad_impl) => {
                             introduce(subs, rank, pools, &vars);
 
                             let problem = TypeError::BadExpr(
@@ -391,12 +399,16 @@ fn solve<'a>(
 
             // TODO(ayazhafiz): presence constraints for Expr2/Type2
             match unify(subs, actual, expected, Mode::EQ) {
-                Success(vars) => {
+                Success {
+                    vars,
+                    must_implement_ability: _,
+                } => {
+                    // TODO(abilities) record deferred ability checks
                     introduce(subs, rank, pools, &vars);
 
                     state
                 }
-                Failure(vars, actual_type, expected_type) => {
+                Failure(vars, actual_type, expected_type, _bad_impl) => {
                     introduce(subs, rank, pools, &vars);
 
                     let problem = TypeError::BadPattern(
@@ -699,12 +711,16 @@ fn solve<'a>(
             let includes = type_to_var(arena, mempool, subs, rank, pools, cached_aliases, &tag_ty);
 
             match unify(subs, actual, includes, Mode::PRESENT) {
-                Success(vars) => {
+                Success {
+                    vars,
+                    must_implement_ability: _,
+                } => {
+                    // TODO(abilities) record deferred ability checks
                     introduce(subs, rank, pools, &vars);
 
                     state
                 }
-                Failure(vars, actual_type, expected_type) => {
+                Failure(vars, actual_type, expected_type, _bad_impl) => {
                     introduce(subs, rank, pools, &vars);
 
                     // TODO: do we need a better error type here?
@@ -1281,7 +1297,7 @@ fn adjust_rank_content(
     use roc_types::subs::FlatType::*;
 
     match content {
-        FlexVar(_) | RigidVar(_) | Error => group_rank,
+        FlexVar(_) | RigidVar(_) | FlexAbleVar(..) | RigidAbleVar(..) | Error => group_rank,
 
         RecursionVar { .. } => group_rank,
 
@@ -1536,7 +1552,7 @@ fn instantiate_rigids_help(
             };
         }
 
-        FlexVar(_) | Error => {}
+        FlexVar(_) | FlexAbleVar(_, _) | Error => {}
 
         RecursionVar { structure, .. } => {
             instantiate_rigids_help(subs, max_rank, pools, structure);
@@ -1547,6 +1563,11 @@ fn instantiate_rigids_help(
             subs.set(copy, make_descriptor(FlexVar(Some(name))));
         }
 
+        RigidAbleVar(name, ability) => {
+            // what it's all about: convert the rigid var into a flex var
+            subs.set(copy, make_descriptor(FlexAbleVar(Some(name), ability)));
+        }
+
         Alias(_, args, real_type_var, _) => {
             for var_index in args.all_variables() {
                 let var = subs[var_index];
@@ -1772,7 +1793,7 @@ fn deep_copy_var_help(
             copy
         }
 
-        FlexVar(_) | Error => copy,
+        FlexVar(_) | FlexAbleVar(_, _) | Error => copy,
 
         RecursionVar {
             opt_name,
@@ -1797,6 +1818,12 @@ fn deep_copy_var_help(
             copy
         }
 
+        RigidAbleVar(name, ability) => {
+            subs.set(copy, make_descriptor(FlexAbleVar(Some(name), ability)));
+
+            copy
+        }
+
         Alias(symbol, mut args, real_type_var, kind) => {
             let mut new_args = Vec::with_capacity(args.all_variables().len());
 
diff --git a/cli/src/build.rs b/cli/src/build.rs
index ab3d7d0c42..c39b55f043 100644
--- a/cli/src/build.rs
+++ b/cli/src/build.rs
@@ -6,6 +6,7 @@ use roc_build::{
 use roc_builtins::bitcode;
 use roc_load::LoadingProblem;
 use roc_mono::ir::OptLevel;
+use roc_reporting::report::RenderTarget;
 use roc_target::TargetInfo;
 use std::path::PathBuf;
 use std::time::{Duration, SystemTime};
@@ -68,6 +69,8 @@ pub fn build_file<'a>(
         src_dir.as_path(),
         subs_by_module,
         target_info,
+        // TODO: expose this from CLI?
+        RenderTarget::ColorTerminal,
     )?;
 
     use target_lexicon::Architecture;
@@ -374,6 +377,8 @@ pub fn check_file(
         src_dir.as_path(),
         subs_by_module,
         target_info,
+        // TODO: expose this from CLI?
+        RenderTarget::ColorTerminal,
     )?;
 
     let buf = &mut String::with_capacity(1024);
diff --git a/docs/Cargo.toml b/docs/Cargo.toml
index d377031ac9..1fe3c231e2 100644
--- a/docs/Cargo.toml
+++ b/docs/Cargo.toml
@@ -21,6 +21,7 @@ roc_parse = { path = "../compiler/parse" }
 roc_target = { path = "../compiler/roc_target" }
 roc_collections = { path = "../compiler/collections" }
 roc_highlight = { path = "../highlight"}
+roc_reporting = { path = "../reporting"}
 bumpalo = { version = "3.8.0", features = ["collections"] }
 snafu = { version = "0.6.10", features = ["backtraces"] }
 peg = "0.8.0"
diff --git a/docs/src/lib.rs b/docs/src/lib.rs
index 7a4a05f0c9..d09134d98d 100644
--- a/docs/src/lib.rs
+++ b/docs/src/lib.rs
@@ -424,6 +424,7 @@ pub fn load_modules_for_files(filenames: Vec<PathBuf>) -> Vec<LoadedModule> {
             src_dir.as_path(),
             Default::default(),
             roc_target::TargetInfo::default_x86_64(), // This is just type-checking for docs, so "target" doesn't matter
+            roc_reporting::report::RenderTarget::ColorTerminal,
         ) {
             Ok(loaded) => modules.push(loaded),
             Err(LoadingProblem::FormattedReport(report)) => {
diff --git a/repl_eval/src/gen.rs b/repl_eval/src/gen.rs
index a5e1fa6dbd..4e8f698c29 100644
--- a/repl_eval/src/gen.rs
+++ b/repl_eval/src/gen.rs
@@ -60,6 +60,7 @@ pub fn compile_to_mono<'a>(
         src_dir,
         exposed_types,
         target_info,
+        roc_reporting::report::RenderTarget::ColorTerminal,
     );
 
     let mut loaded = match loaded {