diff --git a/crates/kind-cli/src/main.rs b/crates/kind-cli/src/main.rs
index d45a9563..e2da1ca9 100644
--- a/crates/kind-cli/src/main.rs
+++ b/crates/kind-cli/src/main.rs
@@ -1,14 +1,12 @@
 #![feature(panic_info_message)]
 
 use std::path::PathBuf;
-use std::time::Instant;
 use std::{fmt, io};
 
 use clap::{Parser, Subcommand};
-use driver::resolution::ResolutionError;
 use kind_driver::session::Session;
 
-use kind_report::data::{Diagnostic, FileCache, Log, Severity};
+use kind_report::data::{FileCache, Log};
 use kind_report::RenderConfig;
 use std::panic;
 
@@ -143,7 +141,7 @@ where
 pub fn render_to_stderr<T, E>(render_config: &RenderConfig, session: &T, err: &E)
 where
     T: FileCache,
-    E: Report,
+    E: Report + ?Sized,
 {
     Report::render(
         err,
@@ -154,77 +152,16 @@ where
     .unwrap();
 }
 
-pub fn compile_in_session<T>(
+pub fn run_in_session<T>(
     render_config: &RenderConfig,
     root: PathBuf,
     file: String,
     compiled: bool,
-    fun: &mut dyn FnMut(&mut Session) -> anyhow::Result<T>,
+    action: &mut dyn FnMut(&mut Session) -> anyhow::Result<T>,
 ) -> anyhow::Result<T> {
-    let (rx, tx) = std::sync::mpsc::channel();
-
-    let mut session = Session::new(root, rx);
-
-    eprintln!();
-
-    render_to_stderr(
-        render_config,
-        &session,
-        &Log::Checking(format!("The file '{}'", file)),
-    );
-
-    let start = Instant::now();
-
-    let res = fun(&mut session);
-
-    let diagnostics = tx.try_iter().collect::<Vec<Box<dyn Diagnostic>>>();
-
-    let mut contains_error = false;
-
-    let mut hidden = 0;
-    let total = diagnostics.len() as u64;
-
-    for diagnostic in diagnostics {
-        if diagnostic.get_severity() == Severity::Error {
-            contains_error = true;
-        }
-
-        let is_root = diagnostic
-            .get_syntax_ctx()
-            .map(|x| x.is_root())
-            .unwrap_or_default();
-
-        if render_config.only_main && !is_root {
-            hidden += 1;
-            continue;
-        }
-
-        render_to_stderr(render_config, &session, &diagnostic)
-    }
-
-    if !contains_error {
-        render_to_stderr(
-            render_config,
-            &session,
-            &if compiled {
-                Log::Compiled(start.elapsed())
-            } else {
-                Log::Checked(start.elapsed())
-            },
-        );
-
-        eprintln!();
-
-        res
-    } else {
-        render_to_stderr(render_config, &session, &Log::Failed(start.elapsed(), total, hidden));
-        eprintln!();
-
-        match res {
-            Ok(_) => Err(ResolutionError.into()),
-            Err(res) => Err(res),
-        }
-    }
+    let log =
+        |session: &Session, report: &dyn Report| render_to_stderr(render_config, session, report);
+    driver::run_in_session(render_config, root, file, compiled, action, &log)
 }
 
 pub fn run_cli(config: Cli) -> anyhow::Result<()> {
@@ -254,7 +191,7 @@ pub fn run_cli(config: Cli) -> anyhow::Result<()> {
 
     match config.command {
         Command::Check { file, coverage } => {
-            compile_in_session(&render_config, root, file.clone(), false, &mut |session| {
+            run_in_session(&render_config, root, file.clone(), false, &mut |session| {
                 let (_, rewrites) = driver::type_check_book(
                     session,
                     &PathBuf::from(file.clone()),
@@ -270,7 +207,7 @@ pub fn run_cli(config: Cli) -> anyhow::Result<()> {
         }
         Command::ToHVM { file } => {
             let result =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                run_in_session(&render_config, root, file.clone(), true, &mut |session| {
                     let book = driver::erase_book(
                         session,
                         &PathBuf::from(file.clone()),
@@ -282,22 +219,21 @@ pub fn run_cli(config: Cli) -> anyhow::Result<()> {
             println!("{}", result);
         }
         Command::Run { file } => {
-            let res =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
-                    let path = PathBuf::from(file.clone());
-                    let book = driver::erase_book(session, &path, entrypoints.clone())?;
-                    driver::check_main_entry(session, &book)?;
-                    let book = driver::compile_book_to_hvm(book, config.trace);
-                    let (result, rewrites) = driver::execute_file(&book.to_string(), config.tids)?;
+            let res = run_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                let path = PathBuf::from(file.clone());
+                let book = driver::erase_book(session, &path, entrypoints.clone())?;
+                driver::check_main_entry(session, &book)?;
+                let book = driver::compile_book_to_hvm(book, config.trace);
+                let (result, rewrites) = driver::execute_file(&book.to_string(), config.tids)?;
 
-                    render_to_stderr(&render_config, session, &Log::Rewrites(rewrites));
+                render_to_stderr(&render_config, session, &Log::Rewrites(rewrites));
 
-                    Ok(result)
-                })?;
+                Ok(result)
+            })?;
             println!("{}", res);
         }
         Command::Show { file } => {
-            compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
+            run_in_session(&render_config, root, file.clone(), true, &mut |session| {
                 driver::to_book(session, &PathBuf::from(file.clone()))
             })
             .map(|res| {
@@ -306,49 +242,44 @@ pub fn run_cli(config: Cli) -> anyhow::Result<()> {
             })?;
         }
         Command::ToKindCore { file } => {
-            let res =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
-                    driver::desugar_book(session, &PathBuf::from(file.clone()))
-                })?;
+            let res = run_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                driver::desugar_book(session, &PathBuf::from(file.clone()))
+            })?;
             print!("{}", res);
         }
         Command::Erase { file } => {
-            let res =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
-                    driver::erase_book(session, &PathBuf::from(file.clone()), entrypoints.clone())
-                })?;
+            let res = run_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                driver::erase_book(session, &PathBuf::from(file.clone()), entrypoints.clone())
+            })?;
             print!("{}", res);
         }
         Command::GenChecker { file, coverage } => {
-            let res =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
-                    driver::check_erasure_book(session, &PathBuf::from(file.clone()))
-                })?;
+            let res = run_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                driver::check_erasure_book(session, &PathBuf::from(file.clone()))
+            })?;
             print!("{}", driver::generate_checker(&res, coverage));
         }
         Command::Eval { file } => {
-            let res =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
-                    let book = driver::desugar_book(session, &PathBuf::from(file.clone()))?;
-                    driver::check_main_desugared_entry(session, &book)?;
-                    let (res, rewrites) = driver::eval_in_checker(&book);
+            let res = run_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                let book = driver::desugar_book(session, &PathBuf::from(file.clone()))?;
+                driver::check_main_desugared_entry(session, &book)?;
+                let (res, rewrites) = driver::eval_in_checker(&book);
 
-                    render_to_stderr(&render_config, session, &Log::Rewrites(rewrites));
+                render_to_stderr(&render_config, session, &Log::Rewrites(rewrites));
 
-                    Ok(res)
-                })?;
+                Ok(res)
+            })?;
             println!("{}", res);
         }
         Command::ToKDL { file, namespace } => {
-            let res =
-                compile_in_session(&render_config, root, file.clone(), true, &mut |session| {
-                    driver::compile_book_to_kdl(
-                        &PathBuf::from(file.clone()),
-                        session,
-                        &namespace.clone().unwrap_or("".to_string()),
-                        entrypoints.clone(),
-                    )
-                })?;
+            let res = run_in_session(&render_config, root, file.clone(), true, &mut |session| {
+                driver::compile_book_to_kdl(
+                    &PathBuf::from(file.clone()),
+                    session,
+                    &namespace.clone().unwrap_or("".to_string()),
+                    entrypoints.clone(),
+                )
+            })?;
             println!("{}", res);
         }
     }
@@ -357,9 +288,12 @@ pub fn run_cli(config: Cli) -> anyhow::Result<()> {
 }
 
 pub fn main() {
-
     panic::set_hook(Box::new(|e| {
-        println!("\n[Error]: internal compiler error '{:?}' at {}", e.message().unwrap(), e.location().unwrap());
+        println!(
+            "\n[Error]: internal compiler error '{:?}' at {}",
+            e.message().unwrap(),
+            e.location().unwrap()
+        );
         println!("Please submit a full report about this error at: https://github.com/HigherOrderCO/Kind/issues/new");
         println!("It would help us a lot :)\n");
     }));
diff --git a/crates/kind-driver/src/lib.rs b/crates/kind-driver/src/lib.rs
index 0efb3d81..c1e1b79c 100644
--- a/crates/kind-driver/src/lib.rs
+++ b/crates/kind-driver/src/lib.rs
@@ -1,14 +1,18 @@
 use checker::eval;
 use diagnostic::{DriverDiagnostic, GenericDriverError};
 use kind_pass::{desugar, erasure, inline::inline_book};
-use kind_report::data::FileCache;
+use kind_report::{
+    data::{FileCache, Log, Severity},
+    report::Report,
+    RenderConfig,
+};
 use kind_span::SyntaxCtxIndex;
 
-use hvm::language::{syntax as backend};
+use hvm::language::syntax as backend;
 use kind_tree::{concrete, desugared, untyped};
 use resolution::ResolutionError;
 use session::Session;
-use std::{path::PathBuf};
+use std::{path::PathBuf, time::Instant};
 
 use kind_checker as checker;
 
@@ -147,9 +151,7 @@ pub fn check_main_desugared_entry(
 
 pub fn execute_file(file: &str, tids: Option<usize>) -> anyhow::Result<(String, u64)> {
     match eval(file, "Main", false, tids) {
-        Ok((res, rewrites)) => {
-            Ok((res.to_string(), rewrites))
-        },
+        Ok((res, rewrites)) => Ok((res.to_string(), rewrites)),
         Err(_) => anyhow::Result::Err(GenericDriverError.into()),
     }
 }
@@ -161,3 +163,69 @@ pub fn eval_in_checker(book: &desugared::Book) -> (String, u64) {
 pub fn generate_checker(book: &desugared::Book, check_coverage: bool) -> String {
     checker::gen_checker(book, check_coverage, book.entrs.keys().cloned().collect())
 }
+
+pub fn run_in_session<T>(
+    render_config: &RenderConfig,
+    root: PathBuf,
+    file: String,
+    compiled: bool,
+    action: &mut dyn FnMut(&mut Session) -> anyhow::Result<T>,
+    log: &dyn Fn(&Session, &dyn Report),
+) -> anyhow::Result<T> {
+    let (rx, tx) = std::sync::mpsc::channel();
+
+    let mut session = Session::new(root, rx);
+
+    log(&session, &Log::Empty);
+    log(&session, &Log::Checking(format!("The file '{}'", file)));
+
+    let start = Instant::now();
+
+    let res = action(&mut session);
+
+    let diagnostics = tx.try_iter().collect::<Vec<_>>();
+
+    let mut contains_error = false;
+
+    let mut hidden = 0;
+    let total = diagnostics.len() as u64;
+
+    for diagnostic in diagnostics {
+        if diagnostic.get_severity() == Severity::Error {
+            contains_error = true;
+        }
+
+        let is_root = diagnostic
+            .get_syntax_ctx()
+            .map(|x| x.is_root())
+            .unwrap_or_default();
+
+        if render_config.only_main && !is_root {
+            hidden += 1;
+            continue;
+        }
+        log(&session, &diagnostic);
+    }
+
+    if !contains_error {
+        log(
+            &session,
+            &if compiled {
+                Log::Compiled(start.elapsed())
+            } else {
+                Log::Checked(start.elapsed())
+            },
+        );
+        log(&session, &Log::Empty);
+
+        res
+    } else {
+        log(&session, &Log::Failed(start.elapsed(), total, hidden));
+        log(&session, &Log::Empty);
+
+        match res {
+            Ok(_) => Err(ResolutionError.into()),
+            Err(res) => Err(res),
+        }
+    }
+}
diff --git a/crates/kind-report/src/data.rs b/crates/kind-report/src/data.rs
index 2c1fb38b..8afe2de3 100644
--- a/crates/kind-report/src/data.rs
+++ b/crates/kind-report/src/data.rs
@@ -73,6 +73,7 @@ pub enum Log {
     Compiled(Duration),
     Rewrites(u64),
     Failed(Duration, u64, u64),
+    Empty,
 }
 
 pub trait Diagnostic {
diff --git a/crates/kind-report/src/report/mode/classic.rs b/crates/kind-report/src/report/mode/classic.rs
index 4f1f6d3c..cfb88d88 100644
--- a/crates/kind-report/src/report/mode/classic.rs
+++ b/crates/kind-report/src/report/mode/classic.rs
@@ -11,11 +11,11 @@ use std::fmt::Write;
 use std::path::PathBuf;
 use yansi::Paint;
 
-fn colorize_code<T: Write + Sized>(
+fn colorize_code(
     markers: &mut [&(Point, Point, &Marker)],
     code_line: &str,
     modify: &dyn Fn(&str) -> String,
-    fmt: &mut T,
+    fmt: &mut dyn Write,
 ) -> std::fmt::Result {
     markers.sort_by(|x, y| x.0.column.cmp(&y.0.column));
     let mut start = 0;
@@ -47,12 +47,12 @@ fn colorize_code<T: Write + Sized>(
     Ok(())
 }
 
-fn mark_inlined<T: Write + Sized>(
+fn mark_inlined(
     prefix: &str,
     code: &str,
     config: &RenderConfig,
     inline_markers: &mut [&(Point, Point, &Marker)],
-    fmt: &mut T,
+    fmt: &mut dyn Write,
 ) -> std::fmt::Result {
     inline_markers.sort_by(|x, y| x.0.column.cmp(&y.0.column));
     let mut start = 0;
@@ -148,7 +148,7 @@ impl Color {
 }
 
 impl Renderable<Classic> for Severity {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         use Severity::*;
 
         let painted = match self {
@@ -162,7 +162,7 @@ impl Renderable<Classic> for Severity {
 }
 
 impl<'a> Renderable<Classic> for Header<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         Renderable::<Classic>::render(self.severity, fmt, cache, config)?;
         fmt.write_str(&Paint::new(&self.title).bold().to_string())?;
         fmt.write_char('\n')
@@ -170,7 +170,7 @@ impl<'a> Renderable<Classic> for Header<'a> {
 }
 
 impl Renderable<Classic> for Subtitle {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         match self {
             Subtitle::Normal(color, phr) | Subtitle::Field(color, phr) => {
                 let bullet = color.colorize(config.chars.bullet);
@@ -194,7 +194,7 @@ impl Renderable<Classic> for Subtitle {
 }
 
 impl<'a> Renderable<Classic> for Word {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         match self {
             Word::Normal(str) => write!(fmt, "{} ", Paint::new(str)),
             Word::Dimmed(str) => write!(fmt, "{} ", Paint::new(str).dimmed()),
@@ -205,7 +205,7 @@ impl<'a> Renderable<Classic> for Word {
 }
 
 impl<'a> Renderable<Classic> for Subtitles<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         if !self.0.is_empty() {
             writeln!(fmt)?;
         }
@@ -215,7 +215,7 @@ impl<'a> Renderable<Classic> for Subtitles<'a> {
 }
 
 impl<'a> Renderable<Classic> for CodeBlock<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, config: &RenderConfig) -> Res {
         let guide = LineGuide::get(self.code);
         let point = guide.find(self.markers.0[0].position.start);
 
@@ -342,7 +342,7 @@ impl<'a> Renderable<Classic> for CodeBlock<'a> {
 }
 
 impl Renderable<Classic> for Log {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         match self {
             Log::Checking(file) => {
                 writeln!(
@@ -390,12 +390,13 @@ impl Renderable<Classic> for Log {
                     u64
                 )
             }
+            Log::Empty => writeln!(fmt, ""),
         }
     }
 }
 
 impl<'a> Renderable<Classic> for Markers<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         let groups = group_markers(&self.0);
         let is_empty = groups.is_empty();
         let current = PathBuf::from(".").canonicalize().unwrap();
@@ -424,7 +425,7 @@ impl<'a> Renderable<Classic> for Markers<'a> {
 }
 
 impl<'a> Renderable<Classic> for Hints<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         for hint in self.0 {
             writeln!(
                 fmt,
@@ -440,7 +441,7 @@ impl<'a> Renderable<Classic> for Hints<'a> {
 }
 
 impl Renderable<Classic> for DiagnosticFrame {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         write!(fmt, " ")?;
 
         Renderable::<Classic>::render(&self.header(), fmt, cache, config)?;
diff --git a/crates/kind-report/src/report/mode/compact.rs b/crates/kind-report/src/report/mode/compact.rs
index cb19dde3..477d428c 100644
--- a/crates/kind-report/src/report/mode/compact.rs
+++ b/crates/kind-report/src/report/mode/compact.rs
@@ -7,10 +7,10 @@ use crate::{report::*, RenderConfig};
 
 use super::{CodeBlock, Compact, Renderable, Res};
 
-fn mark_code<T: Write + Sized>(
+fn mark_code(
     markers: &mut [&(Point, Point, &Marker)],
     code_line: &str,
-    fmt: &mut T,
+    fmt: &mut dyn Write,
 ) -> std::fmt::Result {
     markers.sort_by(|x, y| x.0.column.cmp(&y.0.column));
     let mut start = 0;
@@ -42,7 +42,7 @@ fn mark_code<T: Write + Sized>(
 }
 
 impl<'a> Renderable<Compact> for Word {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         match self {
             Word::Normal(str) => write!(fmt, "{} ", str),
             Word::Dimmed(str) => write!(fmt, "{} ", str),
@@ -53,7 +53,7 @@ impl<'a> Renderable<Compact> for Word {
 }
 
 impl Renderable<Compact> for Subtitle {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         match self {
             Subtitle::Field(_, phr) => writeln!(fmt, "{}", phr.to_lowercase()),
             Subtitle::Normal(_, phr) => writeln!(fmt, "- {}", phr),
@@ -69,7 +69,7 @@ impl Renderable<Compact> for Subtitle {
 }
 
 impl<'a> Renderable<Compact> for Subtitles<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         if !self.0.is_empty() {
             writeln!(fmt)?;
         }
@@ -79,7 +79,7 @@ impl<'a> Renderable<Compact> for Subtitles<'a> {
 }
 
 impl Renderable<Compact> for Severity {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         use Severity::*;
 
         let painted = match self {
@@ -93,13 +93,13 @@ impl Renderable<Compact> for Severity {
 }
 
 impl<'a> Renderable<Compact> for Header<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         writeln!(fmt, "{}", &self.title.to_lowercase())
     }
 }
 
 impl<'a> Renderable<Compact> for CodeBlock<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _8778: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         writeln!(fmt, "location")?;
         let guide = LineGuide::get(self.code);
 
@@ -133,7 +133,7 @@ impl<'a> Renderable<Compact> for CodeBlock<'a> {
 }
 
 impl<'a> Renderable<Compact> for Markers<'a> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         let groups = group_markers(&self.0);
         let current = PathBuf::from(".").canonicalize().unwrap();
 
@@ -155,12 +155,7 @@ impl<'a> Renderable<Compact> for Markers<'a> {
 }
 
 impl Renderable<Compact> for DiagnosticFrame {
-    fn render<U: std::fmt::Write, C: crate::data::FileCache>(
-        &self,
-        fmt: &mut U,
-        cache: &C,
-        config: &crate::RenderConfig,
-    ) -> super::Res {
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         Renderable::<Compact>::render(&self.header(), fmt, cache, config)?;
         Renderable::<Compact>::render(&self.subtitles(), fmt, cache, config)?;
         Renderable::<Compact>::render(&self.markers(), fmt, cache, config)?;
@@ -170,7 +165,7 @@ impl Renderable<Compact> for DiagnosticFrame {
 }
 
 impl Renderable<Compact> for Log {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, _: &C, _: &RenderConfig) -> Res {
+    fn render(&self, fmt: &mut dyn Write, _: &dyn FileCache, _: &RenderConfig) -> Res {
         match self {
             Log::Compiled(_) => writeln!(fmt, "compiled"),
             Log::Checked(_) => writeln!(fmt, "checked"),
diff --git a/crates/kind-report/src/report/mode/mod.rs b/crates/kind-report/src/report/mode/mod.rs
index 4391565f..e1d9953b 100644
--- a/crates/kind-report/src/report/mode/mod.rs
+++ b/crates/kind-report/src/report/mode/mod.rs
@@ -1,7 +1,10 @@
 use std::{fmt::Write, path::Path};
 
-use crate::{data::{FileCache, Diagnostic, DiagnosticFrame, Log}, RenderConfig};
 use super::code::FileMarkers;
+use crate::{
+    data::{Diagnostic, DiagnosticFrame, FileCache, Log},
+    RenderConfig,
+};
 
 pub mod classic;
 pub mod compact;
@@ -35,17 +38,20 @@ pub enum Mode {
 pub(crate) struct CodeBlock<'a> {
     pub code: &'a str,
     pub path: &'a Path,
-    pub markers: &'a FileMarkers
+    pub markers: &'a FileMarkers,
 }
 
 /// A type class for renderable error reports and messages. It's useful
 /// to change easily things without problems.
 pub trait Renderable<T> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res;
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res;
 }
 
-impl<'a, T, E> Renderable<T> for Vec<E> where E : Renderable<T> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+impl<'a, T, E> Renderable<T> for Vec<E>
+where
+    E: Renderable<T>,
+{
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         for elem in self {
             elem.render(fmt, cache, config)?;
         }
@@ -53,14 +59,20 @@ impl<'a, T, E> Renderable<T> for Vec<E> where E : Renderable<T> {
     }
 }
 
-impl<T> Renderable<T> for Box<dyn Diagnostic> where DiagnosticFrame: Renderable<T> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+impl<T> Renderable<T> for Box<dyn Diagnostic>
+where
+    DiagnosticFrame: Renderable<T>,
+{
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         Renderable::<T>::render(&self.to_diagnostic_frame(config), fmt, cache, config)
     }
 }
 
-pub trait Report where Self : Renderable<Classic> + Renderable<Compact> {
-    fn render<U: Write, C: FileCache>(&self, fmt: &mut U, cache: &C, config: &RenderConfig) -> Res {
+pub trait Report
+where
+    Self: Renderable<Classic> + Renderable<Compact>,
+{
+    fn render(&self, fmt: &mut dyn Write, cache: &dyn FileCache, config: &RenderConfig) -> Res {
         match config.mode {
             Mode::Classic => Renderable::<Classic>::render(self, fmt, cache, config),
             Mode::Compact => Renderable::<Compact>::render(self, fmt, cache, config),
@@ -69,4 +81,4 @@ pub trait Report where Self : Renderable<Classic> + Renderable<Compact> {
 }
 
 impl Report for Box<dyn Diagnostic> {}
-impl Report for Log {}
\ No newline at end of file
+impl Report for Log {}