Build fail in bitcoin core on macOS #52

Trying to build bitcoin/bitcoin@a3d7a9864b on macOS results in the following error:

➜  ipc-echo git:(pr/ipc-echo) make
Making all in src
  CXX      ipc/capnp/libbitcoin_ipc_a-echo.capnp.proxy-client.o
In file included from ipc/capnp/echo.capnp.proxy-client.c++:3:
In file included from ./ipc/capnp/echo.capnp.proxy-types.h:6:
./ipc/capnp/echo.capnp.proxy.h:17:35: error: use of undeclared identifier 'interfaces'
    static constexpr auto impl = &interfaces::Echo::echo;
                                  ^
./ipc/capnp/echo.capnp.proxy.h:57:103: error: use of undeclared identifier 'interfaces'
struct ProxyClient<ipc::capnp::messages::Echo> : public ProxyClientCustom<ipc::capnp::messages::Echo, interfaces::Echo>
                                                                                                      ^
./ipc/capnp/echo.capnp.proxy.h:60:11: error: 'ProxyClientCustom' is not a class, namespace, or enumeration
    using ProxyClientCustom::ProxyClientCustom;
          ^
/usr/local/include/mp/proxy.h:77:7: note: 'ProxyClientCustom' declared here
class ProxyClientCustom : public ProxyClientBase<Interface, Impl>
      ^
/usr/local/include/mp/proxy.h:163:14: error: implicit instantiation of undefined template 'mp::FunctionTraits<const auto>'
    : public FunctionTraits<decltype(ProxyMethod<MethodParams>::impl)>
             ^
/usr/local/include/mp/proxy.h:173:41: note: in instantiation of template class 'mp::ProxyMethodTraits<ipc::capnp::messages::Echo::EchoParams, void>' requested here
struct ProxyClientMethodTraits : public ProxyMethodTraits<MethodParams>
                                        ^
./ipc/capnp/echo.capnp.proxy.h:65:14: note: in instantiation of template class 'mp::ProxyClientMethodTraits<ipc::capnp::messages::Echo::EchoParams>' requested here
    typename M1::Result echo(M1::Param<0> echo);
             ^
/usr/local/include/mp/proxy.h:123:8: note: template is declared here
struct FunctionTraits;
       ^
In file included from ipc/capnp/echo.capnp.proxy-client.c++:3:
In file included from ./ipc/capnp/echo.capnp.proxy-types.h:6:
./ipc/capnp/echo.capnp.proxy.h:65:34: error: no template named 'Param' in 'mp::ProxyClientMethodTraits<ipc::capnp::messages::Echo::EchoParams>'
    typename M1::Result echo(M1::Param<0> echo);
                             ~~~~^
./ipc/capnp/echo.capnp.proxy.h:69:103: error: use of undeclared identifier 'interfaces'
struct ProxyServer<ipc::capnp::messages::Echo> : public ProxyServerCustom<ipc::capnp::messages::Echo, interfaces::Echo>
                                                                                                      ^
./ipc/capnp/echo.capnp.proxy.h:72:11: error: 'ProxyServerCustom' is not a class, namespace, or enumeration
    using ProxyServerCustom::ProxyServerCustom;
          ^
/usr/local/include/mp/proxy.h:115:8: note: 'ProxyServerCustom' declared here
struct ProxyServerCustom : public ProxyServerBase<Interface, Impl>
       ^
In file included from ipc/capnp/echo.capnp.proxy-client.c++:3:
In file included from ./ipc/capnp/echo.capnp.proxy-types.h:6:
./ipc/capnp/echo.capnp.proxy.h:74:31: error: unknown type name 'DestroyContext'
    kj::Promise<void> destroy(DestroyContext call_context) override;
                              ^
./ipc/capnp/echo.capnp.proxy.h:75:28: error: unknown type name 'EchoContext'
    kj::Promise<void> echo(EchoContext call_context) override;
                           ^
./ipc/capnp/echo.capnp.proxy.h:79:18: error: use of undeclared identifier 'interfaces'
struct ProxyType<interfaces::Echo>
                 ^
In file included from ipc/capnp/echo.capnp.proxy-client.c++:4:
In file included from /usr/local/include/mp/proxy-types.h:8:
/usr/local/include/mp/proxy-io.h:33:37: warning: parameter 'connection' shadows member inherited from type 'InvokeContext' [-Wshadow-field]
    ClientInvokeContext(Connection& connection, ThreadContext& thread_context)
                                    ^
/usr/local/include/mp/proxy-io.h:27:17: note: declared here
    Connection& connection;
                ^
/usr/local/include/mp/proxy-io.h:160:16: warning: moving a local object in a return statement prevents copy elision [-Wpessimizing-move]
        return std::move(logger);
               ^
/usr/local/include/mp/proxy-io.h:160:16: note: remove std::move call here
        return std::move(logger);
               ^~~~~~~~~~      ~
ipc/capnp/echo.capnp.proxy-client.c++:10:1: error: no type named 'Result' in 'mp::ProxyClientMethodTraits<ipc::capnp::messages::Echo::EchoParams>'; did you mean 'echo_fields::Result'?
ProxyClient<ipc::capnp::messages::Echo>::M1::Result ProxyClient<ipc::capnp::messages::Echo>::echo(M1::Param<0> echo) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
echo_fields::Result
./ipc/capnp/echo.capnp.proxy.h:43:8: note: 'echo_fields::Result' declared here
struct Result
       ^
ipc/capnp/echo.capnp.proxy-client.c++:10:94: error: redefinition of 'echo' as different kind of symbol
ProxyClient<ipc::capnp::messages::Echo>::M1::Result ProxyClient<ipc::capnp::messages::Echo>::echo(M1::Param<0> echo) {
                                                                                             ^
./ipc/capnp/echo.capnp.proxy.h:65:25: note: previous definition is here
    typename M1::Result echo(M1::Param<0> echo);
                        ^
ipc/capnp/echo.capnp.proxy-client.c++:10:103: error: no member named 'Param' in 'mp::ProxyClientMethodTraits<ipc::capnp::messages::Echo::EchoParams>'
ProxyClient<ipc::capnp::messages::Echo>::M1::Result ProxyClient<ipc::capnp::messages::Echo>::echo(M1::Param<0> echo) {
                                                                                                  ~~~~^
ipc/capnp/echo.capnp.proxy-client.c++:10:112: error: use of undeclared identifier 'echo'; did you mean 'ecvt'?
ProxyClient<ipc::capnp::messages::Echo>::M1::Result ProxyClient<ipc::capnp::messages::Echo>::echo(M1::Param<0> echo) {
                                                                                                               ^~~~
                                                                                                               ecvt
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/stdlib.h:201:7: note: 'ecvt' declared here
char    *ecvt(double, int, int *__restrict, int *__restrict); /* LEGACY */
         ^
ipc/capnp/echo.capnp.proxy-client.c++:10:117: error: expected ';' after top level declarator
ProxyClient<ipc::capnp::messages::Echo>::M1::Result ProxyClient<ipc::capnp::messages::Echo>::echo(M1::Param<0> echo) {
                                                                                                                    ^
                                                                                                                    ;
In file included from ipc/capnp/echo.capnp.proxy-client.c++:4:
/usr/local/include/mp/proxy-types.h:1365:23: error: no member named 'm_context' in 'mp::ProxyClient<ipc::capnp::messages::Echo>'
    if (!proxy_client.m_context.connection) {
         ~~~~~~~~~~~~ ^
ipc/capnp/echo.capnp.proxy-client.c++:8:5: note: in instantiation of function template specialization 'mp::clientInvoke<mp::ProxyClient<ipc::capnp::messages::Echo>, capnp::Request<ipc::capnp::messages::Echo::DestroyParams, ipc::capnp::messages::Echo::DestroyResults> (ipc::capnp::messages::Echo::Client::*)(kj::Maybe<capnp::MessageSize>), mp::ClientParam<mp::Accessor<mp::echo_fields::Context, 17>> >' requested here
    clientInvoke(*this, &ipc::capnp::messages::Echo::Client::destroyRequest, MakeClientParam<Accessor<echo_fields::Context, FIELD_IN | FIELD_BOXED>>());
    ^
In file included from ipc/capnp/echo.capnp.proxy-client.c++:4:
/usr/local/include/mp/proxy-types.h:1370:64: error: no member named 'm_context' in 'mp::ProxyClient<ipc::capnp::messages::Echo>'
        g_thread_context.thread_name = ThreadName(proxy_client.m_context.connection->m_loop.m_exe_name);
                                                  ~~~~~~~~~~~~ ^
/usr/local/include/mp/proxy-types.h:1381:22: error: no member named 'm_context' in 'mp::ProxyClient<ipc::capnp::messages::Echo>'
        proxy_client.m_context.connection->m_loop.logPlain()
        ~~~~~~~~~~~~ ^
/usr/local/include/mp/proxy-types.h:1385:54: error: no member named 'm_context' in 'mp::ProxyClient<ipc::capnp::messages::Echo>'
    ClientInvokeContext invoke_context{*proxy_client.m_context.connection, g_thread_context};
                                        ~~~~~~~~~~~~ ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
2 warnings and 20 errors generated.
make[2]: *** [ipc/capnp/libbitcoin_ipc_a-echo.capnp.proxy-client.o] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all-recursive] Error 1

I've followed 805eb73 build and install instructions.

On the bitcoin folder, I've made a fresh clone and configure.

Thanks for reporting this!

Trying to build bitcoin/bitcoin@a3d7a98 on macOS results in the following error:

I am able to reproduce this, and this is caused by #43. The reason it happens is that the version of https://github.com/bitcoin/bitcoin/pull/19160 built here is a few months old, originally pushed 2020-11-24, and not compatible with the current version of libmultiprocess after #43.

There are three ways to fix it:

1. Update https://github.com/bitcoin/bitcoin/pull/19160 pull from a3d7a9864b1 pr/ipc-echo.19 to pr/ipc-echo.24 or newer.

2. Downgrade libmultiprocess from the version you have installed to an older version preceding PR #43

3. Apply the following changes manually:

git diff pr/ipc-echo.19..pr/ipc-echo.24 src/ipc/capnp/*.capnp
diff --git a/src/ipc/capnp/echo.capnp b/src/ipc/capnp/echo.capnp
index cedf6f2718e..1bdd81321ca 100644
--- a/src/ipc/capnp/echo.capnp
+++ b/src/ipc/capnp/echo.capnp
@@ -8,6 +8,8 @@ using Cxx = import "/capnp/c++.capnp";
 $Cxx.namespace("ipc::capnp::messages");
 
 using Proxy = import "/mp/proxy.capnp";
+$Proxy.include("interfaces/echo.h");
+$Proxy.include("ipc/capnp/echo.capnp.h");
 
 interface Echo $Proxy.wrap("interfaces::Echo") {
     destroy [@0](/bitcoin-core-multiprocess/contributor/0/) (context :Proxy.Context) -> ();
diff --git a/src/ipc/capnp/init.capnp b/src/ipc/capnp/init.capnp
index 06f767b02c5..78f1c7f8cd9 100644
--- a/src/ipc/capnp/init.capnp
+++ b/src/ipc/capnp/init.capnp
@@ -9,6 +9,8 @@ $Cxx.namespace("ipc::capnp::messages");
 
 using Echo = import "echo.capnp";
 using Proxy = import "/mp/proxy.capnp";
+$Proxy.include("ipc/capnp/init.h");
+$Proxy.includeTypes("ipc/capnp/init-types.h");
 
 interface Init $Proxy.wrap("interfaces::Init") {
     construct [@0](/bitcoin-core-multiprocess/contributor/0/) (threadMap: Proxy.ThreadMap) -> (threadMap :Proxy.ThreadMap);

🤦 I thought I was on the latest version, not sure what happened as I usually fetch the latest version. Sorry for the noise!

Not noise at all! Definitely could have provided clearer build errors here. I filed https://github.com/chaincodelabs/libmultiprocess/issues/54 to track this.