From 3db744ef9f79f188ccc7b42ce7a1e174ed445169 Mon Sep 17 00:00:00 2001
From: Wolf Vollprecht <w.vollprecht@gmail.com>
Date: Wed, 4 Dec 2024 16:12:13 +0100
Subject: [PATCH 1/2] overwrite previous build more lazily

---
 src/build.rs         |  5 +++++
 src/render/solver.rs | 24 ++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/build.rs b/src/build.rs
index 4bfd3a20..973525ab 100644
--- a/src/build.rs
+++ b/src/build.rs
@@ -114,6 +114,11 @@ pub async fn run_build(
 
     let directories = output.build_configuration.directories.clone();
 
+    // if the work directory already exists, we should remove it
+    if directories.work_dir.exists() {
+        fs_err::remove_dir_all(&directories.work_dir).into_diagnostic()?;
+    }
+
     let output = if output.recipe.cache.is_some() {
         output.build_or_fetch_cache(tool_configuration).await?
     } else {
diff --git a/src/render/solver.rs b/src/render/solver.rs
index 39db5417..330cfe26 100644
--- a/src/render/solver.rs
+++ b/src/render/solver.rs
@@ -11,11 +11,11 @@ use futures::FutureExt;
 use indicatif::{HumanBytes, ProgressBar, ProgressStyle};
 use itertools::Itertools;
 use rattler::install::{DefaultProgressFormatter, IndicatifReporter, Installer};
-use rattler_conda_types::{Channel, ChannelUrl, MatchSpec, Platform, RepoDataRecord};
+use rattler_conda_types::{Channel, ChannelUrl, MatchSpec, Platform, PrefixRecord, RepoDataRecord};
 use rattler_solve::{resolvo::Solver, ChannelPriority, SolveStrategy, SolverImpl, SolverTask};
 use url::Url;
 
-use crate::{metadata::PlatformWithVirtualPackages, tool_configuration};
+use crate::{metadata::PlatformWithVirtualPackages, packaging::Files, tool_configuration};
 
 fn print_as_table(packages: &[RepoDataRecord]) {
     let mut table = Table::new();
@@ -311,12 +311,32 @@ pub async fn install_packages(
             )
         })?;
 
+    let installed_packages = PrefixRecord::collect_from_prefix(target_prefix)?;
+
+    if !installed_packages.is_empty() && name.starts_with("host") {
+        // we have to clean up extra files in the prefix
+        let extra_files =
+            Files::from_prefix(target_prefix, &Default::default(), &Default::default())?;
+
+        tracing::info!(
+            "Cleaning up {} files in the prefix from a previous build.",
+            extra_files.new_files.len()
+        );
+
+        for f in extra_files.new_files {
+            if !f.is_dir() {
+                fs_err::remove_file(target_prefix.join(f))?;
+            }
+        }
+    }
+
     tracing::info!("\nInstalling {name} environment\n");
     Installer::new()
         .with_download_client(tool_configuration.client.clone())
         .with_target_platform(target_platform)
         .with_execute_link_scripts(true)
         .with_package_cache(tool_configuration.package_cache.clone())
+        .with_installed_packages(installed_packages)
         .with_reporter(
             IndicatifReporter::builder()
                 .with_multi_progress(

From 7d54a050277f6cfb801b301e49e31e472ff3d6ab Mon Sep 17 00:00:00 2001
From: Wolf Vollprecht <w.vollprecht@gmail.com>
Date: Wed, 4 Dec 2024 17:04:28 +0100
Subject: [PATCH 2/2] fix up

---
 src/build.rs    |  7 +------
 src/metadata.rs | 11 ++++++++---
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/build.rs b/src/build.rs
index 973525ab..52c945b1 100644
--- a/src/build.rs
+++ b/src/build.rs
@@ -105,7 +105,7 @@ pub async fn run_build(
     output
         .build_configuration
         .directories
-        .create_build_dir()
+        .create_build_dir(true)
         .into_diagnostic()?;
 
     let span = tracing::info_span!("Running build for", recipe = output.identifier());
@@ -114,11 +114,6 @@ pub async fn run_build(
 
     let directories = output.build_configuration.directories.clone();
 
-    // if the work directory already exists, we should remove it
-    if directories.work_dir.exists() {
-        fs_err::remove_dir_all(&directories.work_dir).into_diagnostic()?;
-    }
-
     let output = if output.recipe.cache.is_some() {
         output.build_or_fetch_cache(tool_configuration).await?
     } else {
diff --git a/src/metadata.rs b/src/metadata.rs
index 1fce87d1..0735fb6f 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -185,8 +185,13 @@ impl Directories {
     }
 
     /// Creates the build directory.
-    pub fn create_build_dir(&self) -> Result<(), std::io::Error> {
-        fs::create_dir_all(self.build_dir.join("work"))?;
+    pub fn create_build_dir(&self, remove_existing_work_dir: bool) -> Result<(), std::io::Error> {
+        if remove_existing_work_dir && self.work_dir.exists() {
+            fs::remove_dir_all(&self.work_dir)?;
+        }
+
+        fs::create_dir_all(&self.work_dir)?;
+
         Ok(())
     }
 
@@ -784,7 +789,7 @@ mod test {
             &chrono::Utc::now(),
         )
         .unwrap();
-        directories.create_build_dir().unwrap();
+        directories.create_build_dir(false).unwrap();
 
         // test yaml roundtrip
         let yaml = serde_yaml::to_string(&directories).unwrap();