diff --git a/lix/libexpr/flake/flake.cc b/lix/libexpr/flake/flake.cc
index 374852607..eb91d4b62 100644
--- a/lix/libexpr/flake/flake.cc
+++ b/lix/libexpr/flake/flake.cc
@@ -853,9 +853,13 @@ LockedFlake lockFlake(
                                 commitMessage = cm;
                             }
 
-                            topRef.input.putFile(
-                                CanonPath((topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock"),
-                                newLockFileS, commitMessage);
+                            state.aio.blockOn(topRef.input.putFile(
+                                CanonPath(
+                                    (topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock"
+                                ),
+                                newLockFileS,
+                                commitMessage
+                            ));
                         }
 
                         /* Rewriting the lockfile changed the top-level
diff --git a/lix/libfetchers/fetchers.cc b/lix/libfetchers/fetchers.cc
index 4a76ed2dc..30c9ce47b 100644
--- a/lix/libfetchers/fetchers.cc
+++ b/lix/libfetchers/fetchers.cc
@@ -3,6 +3,7 @@
 #include "lix/libstore/store-api.hh"
 #include "lix/libutil/async.hh"
 #include "lix/libutil/json.hh"
+#include "lix/libutil/result.hh"
 #include "lix/libutil/source-path.hh"
 #include "lix/libfetchers/fetch-to-store.hh"
 
@@ -220,10 +221,13 @@ Input Input::applyOverrides(
     return scheme->applyOverrides(*this, ref, rev);
 }
 
-void Input::clone(const Path & destDir) const
-{
+kj::Promise<Result<void>> Input::clone(const Path & destDir) const
+try {
     assert(scheme);
-    scheme->clone(*this, destDir);
+    TRY_AWAIT(scheme->clone(*this, destDir));
+    co_return result::success();
+} catch (...) {
+    co_return result::current_exception();
 }
 
 std::optional<Path> Input::getSourcePath() const
@@ -232,13 +236,15 @@ std::optional<Path> Input::getSourcePath() const
     return scheme->getSourcePath(*this);
 }
 
-void Input::putFile(
-    const CanonPath & path,
-    std::string_view contents,
-    std::optional<std::string> commitMsg) const
-{
+kj::Promise<Result<void>> Input::putFile(
+    const CanonPath & path, std::string_view contents, std::optional<std::string> commitMsg
+) const
+try {
     assert(scheme);
-    return scheme->putFile(*this, path, contents, commitMsg);
+    TRY_AWAIT(scheme->putFile(*this, path, contents, commitMsg));
+    co_return result::success();
+} catch (...) {
+    co_return result::current_exception();
 }
 
 std::string Input::getName() const
@@ -345,18 +351,22 @@ std::optional<Path> InputScheme::getSourcePath(const Input & input) const
     return {};
 }
 
-void InputScheme::putFile(
+kj::Promise<Result<void>> InputScheme::putFile(
     const Input & input,
     const CanonPath & path,
     std::string_view contents,
-    std::optional<std::string> commitMsg) const
-{
+    std::optional<std::string> commitMsg
+) const
+try {
     throw Error("input '%s' does not support modifying file '%s'", input.to_string(), path);
+} catch (...) {
+    co_return result::current_exception();
 }
 
-void InputScheme::clone(const Input & input, const Path & destDir) const
-{
+kj::Promise<Result<void>> InputScheme::clone(const Input & input, const Path & destDir) const
+try {
     throw Error("do not know how to clone input '%s'", input.to_string());
+} catch (...) {
+    co_return result::current_exception();
 }
-
 }
diff --git a/lix/libfetchers/fetchers.hh b/lix/libfetchers/fetchers.hh
index 77bbc8805..e9ee88555 100644
--- a/lix/libfetchers/fetchers.hh
+++ b/lix/libfetchers/fetchers.hh
@@ -102,7 +102,7 @@ public:
         std::optional<std::string> ref,
         std::optional<Hash> rev) const;
 
-    void clone(const Path & destDir) const;
+    kj::Promise<Result<void>> clone(const Path & destDir) const;
 
     std::optional<Path> getSourcePath() const;
 
@@ -110,10 +110,9 @@ public:
      * Write a file to this input, for input types that support
      * writing. Optionally commit the change (for e.g. Git inputs).
      */
-    void putFile(
-        const CanonPath & path,
-        std::string_view contents,
-        std::optional<std::string> commitMsg) const;
+    kj::Promise<Result<void>> putFile(
+        const CanonPath & path, std::string_view contents, std::optional<std::string> commitMsg
+    ) const;
 
     std::string getName() const;
 
@@ -160,15 +159,16 @@ struct InputScheme
         std::optional<std::string> ref,
         std::optional<Hash> rev) const;
 
-    virtual void clone(const Input & input, const Path & destDir) const;
+    virtual kj::Promise<Result<void>> clone(const Input & input, const Path & destDir) const;
 
     virtual std::optional<Path> getSourcePath(const Input & input) const;
 
-    virtual void putFile(
+    virtual kj::Promise<Result<void>> putFile(
         const Input & input,
         const CanonPath & path,
         std::string_view contents,
-        std::optional<std::string> commitMsg) const;
+        std::optional<std::string> commitMsg
+    ) const;
 
     virtual kj::Promise<Result<std::pair<StorePath, Input>>>
     fetch(ref<Store> store, const Input & input) = 0;
diff --git a/lix/libfetchers/git.cc b/lix/libfetchers/git.cc
index d7a2a9b2a..94e2344ba 100644
--- a/lix/libfetchers/git.cc
+++ b/lix/libfetchers/git.cc
@@ -7,6 +7,7 @@
 #include "lix/libstore/globals.hh"
 #include "lix/libfetchers/builtin-fetchers.hh"
 #include "lix/libutil/processes.hh"
+#include "lix/libutil/result.hh"
 #include "lix/libutil/tarfile.hh"
 #include "lix/libstore/store-api.hh"
 #include "lix/libstore/temporary-dir.hh"
@@ -398,8 +399,8 @@ struct GitInputScheme : InputScheme
         return res;
     }
 
-    void clone(const Input & input, const Path & destDir) const override
-    {
+    kj::Promise<Result<void>> clone(const Input & input, const Path & destDir) const override
+    try {
         auto [isLocal, actualUrl] = getActualUrl(input);
 
         Strings args = {"clone"};
@@ -416,6 +417,9 @@ struct GitInputScheme : InputScheme
         args.push_back(destDir);
 
         runProgram("git", true, args, true);
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 
     std::optional<Path> getSourcePath(const Input & input) const override
@@ -426,12 +430,13 @@ struct GitInputScheme : InputScheme
         return {};
     }
 
-    void putFile(
+    kj::Promise<Result<void>> putFile(
         const Input & input,
         const CanonPath & path,
         std::string_view contents,
-        std::optional<std::string> commitMsg) const override
-    {
+        std::optional<std::string> commitMsg
+    ) const override
+    try {
         auto root = getSourcePath(input);
         if (!root)
             throw Error("cannot commit '%s' to Git repository '%s' because it's not a working tree", path, input.to_string());
@@ -461,6 +466,10 @@ struct GitInputScheme : InputScheme
                     { "-C", *root, "--git-dir", gitDir, "commit", std::string(path.rel()), "-F", msgPath }, true);
             }
         }
+
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 
     std::pair<bool, std::string> getActualUrl(const Input & input) const
diff --git a/lix/libfetchers/github.cc b/lix/libfetchers/github.cc
index 7623c1e0e..970e1e345 100644
--- a/lix/libfetchers/github.cc
+++ b/lix/libfetchers/github.cc
@@ -4,6 +4,7 @@
 #include "lix/libstore/store-api.hh"
 #include "lix/libutil/async.hh"
 #include "lix/libutil/regex.hh"
+#include "lix/libutil/result.hh"
 #include "lix/libutil/types.hh"
 #include "lix/libutil/url-parts.hh"
 #include "lix/libutil/git.hh"
@@ -309,13 +310,17 @@ struct GitHubInputScheme : GitArchiveInputScheme
         return DownloadUrl { url, headers };
     }
 
-    void clone(const Input & input, const Path & destDir) const override
-    {
+    kj::Promise<Result<void>> clone(const Input & input, const Path & destDir) const override
+    try {
         auto host = getHost(input);
-        Input::fromURL(fmt("git+https://%s/%s/%s.git",
-                host, getOwner(input), getRepo(input)))
-            .applyOverrides(input.getRef(), input.getRev())
-            .clone(destDir);
+        TRY_AWAIT(
+            Input::fromURL(fmt("git+https://%s/%s/%s.git", host, getOwner(input), getRepo(input)))
+                .applyOverrides(input.getRef(), input.getRev())
+                .clone(destDir)
+        );
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 
     Headers makeHeadersWithAuthTokens(const std::string & host) const
@@ -391,14 +396,19 @@ struct GitLabInputScheme : GitArchiveInputScheme
         return DownloadUrl { url, headers };
     }
 
-    void clone(const Input & input, const Path & destDir) const override
-    {
+    kj::Promise<Result<void>> clone(const Input & input, const Path & destDir) const override
+    try {
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("gitlab.com");
         // FIXME: get username somewhere
-        Input::fromURL(fmt("git+https://%s/%s/%s.git",
-                host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo")))
-            .applyOverrides(input.getRef(), input.getRev())
-            .clone(destDir);
+        TRY_AWAIT(Input::fromURL(fmt("git+https://%s/%s/%s.git",
+                                     host,
+                                     getStrAttr(input.attrs, "owner"),
+                                     getStrAttr(input.attrs, "repo")))
+                      .applyOverrides(input.getRef(), input.getRev())
+                      .clone(destDir));
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 };
 
@@ -485,13 +495,18 @@ struct SourceHutInputScheme : GitArchiveInputScheme
         return DownloadUrl { url, headers };
     }
 
-    void clone(const Input & input, const Path & destDir) const override
-    {
+    kj::Promise<Result<void>> clone(const Input & input, const Path & destDir) const override
+    try {
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("git.sr.ht");
-        Input::fromURL(fmt("git+https://%s/%s/%s",
-                host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo")))
-            .applyOverrides(input.getRef(), input.getRev())
-            .clone(destDir);
+        TRY_AWAIT(Input::fromURL(fmt("git+https://%s/%s/%s",
+                                     host,
+                                     getStrAttr(input.attrs, "owner"),
+                                     getStrAttr(input.attrs, "repo")))
+                      .applyOverrides(input.getRef(), input.getRev())
+                      .clone(destDir));
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 };
 
diff --git a/lix/libfetchers/mercurial.cc b/lix/libfetchers/mercurial.cc
index 09c8ece12..11682bfbe 100644
--- a/lix/libfetchers/mercurial.cc
+++ b/lix/libfetchers/mercurial.cc
@@ -6,6 +6,7 @@
 #include "lix/libutil/processes.hh"
 #include "lix/libstore/store-api.hh"
 #include "lix/libstore/temporary-dir.hh"
+#include "lix/libutil/result.hh"
 #include "lix/libutil/url-parts.hh"
 #include "lix/libutil/users.hh"
 
@@ -128,12 +129,13 @@ struct MercurialInputScheme : InputScheme
         return {};
     }
 
-    void putFile(
+    kj::Promise<Result<void>> putFile(
         const Input & input,
         const CanonPath & path,
         std::string_view contents,
-        std::optional<std::string> commitMsg) const override
-    {
+        std::optional<std::string> commitMsg
+    ) const override
+    try {
         auto [isLocal, repoPath] = getActualUrl(input);
         if (!isLocal)
             throw Error("cannot commit '%s' to Mercurial repository '%s' because it's not a working tree", path, input.to_string());
@@ -149,6 +151,9 @@ struct MercurialInputScheme : InputScheme
         if (commitMsg)
             runHg(
                 { "commit", absPath.abs(), "-m", *commitMsg });
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 
     std::pair<bool, std::string> getActualUrl(const Input & input) const
diff --git a/lix/libfetchers/path.cc b/lix/libfetchers/path.cc
index c2da221b5..ce1b9f01f 100644
--- a/lix/libfetchers/path.cc
+++ b/lix/libfetchers/path.cc
@@ -3,6 +3,7 @@
 #include "lix/libstore/store-api.hh"
 #include "lix/libutil/archive.hh"
 #include "lix/libutil/async-io.hh"
+#include "lix/libutil/result.hh"
 
 namespace nix::fetchers {
 
@@ -82,13 +83,17 @@ struct PathInputScheme : InputScheme
         return getStrAttr(input.attrs, "path");
     }
 
-    void putFile(
+    kj::Promise<Result<void>> putFile(
         const Input & input,
         const CanonPath & path,
         std::string_view contents,
-        std::optional<std::string> commitMsg) const override
-    {
+        std::optional<std::string> commitMsg
+    ) const override
+    try {
         writeFile((CanonPath(getAbsPath(input)) + path).abs(), contents);
+        co_return result::success();
+    } catch (...) {
+        co_return result::current_exception();
     }
 
     CanonPath getAbsPath(const Input & input) const
diff --git a/lix/nix/flake.cc b/lix/nix/flake.cc
index c2f83ba97..6e135b276 100644
--- a/lix/nix/flake.cc
+++ b/lix/nix/flake.cc
@@ -1043,7 +1043,7 @@ struct CmdFlakeClone : FlakeCommand
         if (destDir.empty())
             throw Error("missing flag '--dest'");
 
-        aio().blockOn(getFlakeRef().resolve(store)).input.clone(destDir);
+        aio().blockOn(aio().blockOn(getFlakeRef().resolve(store)).input.clone(destDir));
     }
 };