feat(snix/castore): builtins.fetchGit

This adds builtins.fetchgit and the backing git import based on
gitoxide.

The implementation uses a temporary directory to clone a bare git
repository in a separate thread. gitoxide does not yet have full async
support for cloning ssh-based repositories, which is why a separate
thread is used.

builtins.fetchgit has more requirements than the Nix equivalent. rev is
always required and a sha256 to check is not supported at this time.

Change-Id: I035756c300bd694ab4ca4640ba941e4603925523

Author: domenkozar

snix/Cargo.lock

@@ -72,6 +72,7 @@ fastcdc = "3.1.0"
 fuse-backend-rs = "0.12.0"
 futures = "0.3.30"
 genawaiter = { version = "0.99.1", default-features = false }
+gix = "0.67.0"
 glob = "0.3.1"
 hex-literal = "0.4.1"
 http = "1.1.0"

snix/Cargo.nix

@@ -23,7 +23,14 @@ thiserror.workspace = true
 tokio-stream = { workspace = true, features = ["fs", "net"] }
 tokio-util = { workspace = true, features = ["io", "io-util", "codec"] }
 tokio-tar.workspace = true
-tokio = { workspace = true, features = ["fs", "macros", "net", "rt", "rt-multi-thread", "signal"] }
+tokio = { workspace = true, features = [
+    "fs",
+    "macros",
+    "net",
+    "rt",
+    "rt-multi-thread",
+    "signal",
+] }
 toml = { version = "0.8.19", optional = true }
 tonic.workspace = true
 tower.workspace = true
@@ -56,6 +63,12 @@ virtio-bindings = { workspace = true, optional = true }
 wu-manber.workspace = true
 auto_impl = "1.2.0"
 hashbrown = "0.15.2"
+gix = { workspace = true, features = [
+    "blocking-network-client",
+    "blocking-http-transport-reqwest",
+] }
+gix-archive = "0.16.0"
+tempfile.workspace = true
 
 [build-dependencies]
 prost-build.workspace = true
@@ -64,7 +77,6 @@ tonic-build.workspace = true
 [dev-dependencies]
 async-process.workspace = true
 rstest.workspace = true
-tempfile.workspace = true
 tokio-retry.workspace = true
 hex-literal.workspace = true
 rstest_reuse.workspace = true
@@ -75,22 +87,22 @@ tokio-test.workspace = true
 [features]
 default = ["cloud"]
 cloud = [
-  "dep:bigtable_rs",
-  "object_store/aws",
-  "object_store/azure",
-  "object_store/gcp",
+    "dep:bigtable_rs",
+    "object_store/aws",
+    "object_store/azure",
+    "object_store/gcp",
 ]
 fs = ["dep:fuse-backend-rs", "dep:threadpool", "dep:libc"]
 virtiofs = [
-  "fs",
-  "dep:vhost",
-  "dep:vhost-user-backend",
-  "dep:virtio-queue",
-  "dep:vm-memory",
-  "dep:vmm-sys-util",
-  "dep:virtio-bindings",
-  "fuse-backend-rs?/vhost-user-fs", # impl FsCacheReqHandler for SlaveFsCacheReq
-  "fuse-backend-rs?/virtiofs",
+    "fs",
+    "dep:vhost",
+    "dep:vhost-user-backend",
+    "dep:virtio-queue",
+    "dep:vm-memory",
+    "dep:vmm-sys-util",
+    "dep:virtio-bindings",
+    "fuse-backend-rs?/vhost-user-fs", # impl FsCacheReqHandler for SlaveFsCacheReq
+    "fuse-backend-rs?/virtiofs",
 ]
 fuse = ["fs"]
 tonic-reflection = ["dep:tonic-reflection"]