similar here, trying to build for Ubuntu:

xxx@DESKTOP-ES15K2K:~/git/vpnkit$ make
opam exec -- dune build --profile release
make[1]: Entering directory '/home/xxx/git/vpnkit/_build/default'
GEN src/bin/version.ml
make[1]: Leaving directory '/home/xxx/git/vpnkit/_build/default'
File "src/hostnet/hostnet_dns.ml", line 260, characters 6-46:
260 | Ethernet__Ethernet_wire.set_ethernet_src smac 0 frame;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Unbound module Ethernet__Ethernet_wire
File "dune", line 14, characters 0-127:
14 | (rule
15 | (target licenses.json)
16 | (deps deps.csv (:gen ./scripts/licenses.exe))
17 | (action (run %{gen} -out %{target} -in %{deps})))
Fatal error: exception Failure("unknown licenses for uri-sexp.4.4.0, uri.4.4.0, sha.1.15.4, re.1.11.0, ptime.1.1.0, ppx_cstruct.6.2.0, ounit2.2.2.7, ounit.2.2.7, optint.0.3.0, ocaml-system.4.13.1, num.1.5, mirage-kv.6.1.1, metrics.0.4.1, menhirSdk.20231231, menhirLib.20231231, menhirCST.20231231, menhir.20231231, macaddr-sexp.5.5.0, macaddr-cstruct.5.5.0, macaddr.5.5.0, lwt.5.7.0, luv_unix.0.5.1, luv.0.5.12, jsonm.1.0.2, ipaddr-sexp.5.5.0, ipaddr.5.5.0, ethernet.3.2.0, dune-configurator.3.13.0, dune.3.13.0, ctypes.0.21.1, cstruct-sexp.6.2.0, cstruct-lwt.6.2.0, cstruct.6.2.0, csexp.1.5.2, cohttp-lwt.5.3.0, cohttp.5.3.1, bigstringaf.0.9.1, base64.3.5.1, arp.3.1.0, angstrom.0.16.0")
make: *** [Makefile:6: vpnkit.exe] Error 1

Looks like this is due to mirage/ethernet@61dfc14

I have managed to pin the dependencies to a state that builds successfully without changing the codebase. Here is the diff I have so far

diff --git a/vpnkit.opam b/vpnkit.opam
index 1c5b6ef2..b9384b0b 100644
--- a/vpnkit.opam
+++ b/vpnkit.opam
@@ -1,3 +1,4 @@
+version: "0.5.0"
 opam-version: "2.0"
 maintainer: "David Scott <dave.scott@docker.com>"
 authors: [
@@ -23,12 +24,12 @@ build: [
 
 depends: [
   "ocaml" {>="4.08.0"}
-  "dune"
+  "dune" {< "3.1.0"}
   "alcotest" {with-test}
   "ounit" {with-test}
   "tar" {>= "1.0.1"}
   "ipaddr" {>= "5.0.1"}
-  "lwt" {>= "5.4.0"}
+  "lwt" {>= "5.4.0" & < "5.6.0"}
   "luv"
   "luv_unix"
   "tcpip" {>= "7.0.0"}
@@ -36,15 +37,15 @@ depends: [
   "cstruct" {>= "6.0.0"}
   "pcap-format" {>= "0.4.0"}
   "cmdliner" {< "1.1.0"}
-  "charrua" {>= "1.3.0"}
-  "charrua-client"
-  "charrua-server"
+  "charrua" {>= "1.3.0" }
+  "charrua-client" {>= "1.3.0" }
+  "charrua-server"{>= "1.3.0" }
   "hvsock" {>= "2.0.0"}
   "fd-send-recv" {>= "2.0.0"}
   "logs"
   "fmt"
   "astring"
-  "ethernet" {>= "3.0.0"}
+  "ethernet" {>= "3.0.0" & < "3.1.0"}
   "arp" {>= "3.0.0"}
   "mirage-entropy" {>= "0.5.0"}
   "mirage-kv" {>= "4.0.0"}
@@ -54,7 +55,7 @@ depends: [
   "mirage-stack"
   "cohttp-lwt" {>= "0.99.0"}
   "protocol-9p" {>= "2.0.0"}
-  "mirage-vnetif" {>= "0.5.0"}
+  "mirage-vnetif" {>= "0.5.0" & < "0.6.0"}
   "io-page-unix"
   "uuidm"
   "ezjsonm" {>= "0.4.0"}
@@ -66,6 +67,7 @@ depends: [
   "mirage-random-stdlib"
   "re" {>= "1.9.0"}
   "ppx_inline_test"
+  "result"
 ]
 synopsis: "VPN-friendly networking devices for HyperKit"
 description: """

@LaurentGoderre pinning the dependencies sounds like a good initial step! Would you have time to create a PR? We could update the code to use the latest versions later (since that will be more invasive)

@djs55 that is what I am working on yes but the e2e tests are failing so I am trying to resolve it

#641

@djs55 I believe we can close this now