Compilation error using zig-bootstrap and latest master zig

[mathk]

Hi I pull the latest

zig-bootstrap: 11ba677d7 (HEAD → master, origin/master, origin/HEAD) update zig sources to 0.16.0-dev.1634+b27bdd5af

and zig: de25a6ffee (HEAD → master, upstream/master) Merge pull request ‘std: delete os.environ, os.argv, add new parameter to main, move process API to std.Io’ (#30644) from juice into master

And run this command:

../zig-bootstrap/out/zig-x86_64-linux-gnu-baseline/zig build
-p stage3
–search-prefix “../zig-bootstrap/out/x86_64-linux-gnu-baseline”
–zig-lib-dir “lib”
-Dstatic-llvm

It give the following error:

install
└─ install zig
   └─ compile exe zig Debug native 3 errors
lib/std/Io.zig:2052:23: error: expected type 'error{Canceled,Closed}!T', found 'T'
            return buf[0];
                   ~~~^~~
lib/std/Io.zig:2052:23: note: T = error{AccessDenied,AddressFamilyUnsupported,AddressUnavailable,Canceled,ConnectionPending,ConnectionRefused,ConnectionResetByPeer,HostUnreachable,NetworkDown,NetworkUnreachable,OptionUnsupported,ProcessFdQuotaExceeded,ProtocolUnsupportedByAddressFamily,ProtocolUnsupportedBySystem,SocketModeUnsupported,SystemFdQuotaExceeded,SystemResources,Timeout,Unexpected,UnsupportedClock,WouldBlock}!Io.net.Stream
lib/std/Io.zig:2052:23: note: error union payload 'Io.net.Stream' cannot cast into error union payload 'error{AccessDenied,AddressFamilyUnsupported,AddressUnavailable,Canceled,ConnectionPending,ConnectionRefused,ConnectionResetByPeer,HostUnreachable,NetworkDown,NetworkUnreachable,OptionUnsupported,ProcessFdQuotaExceeded,ProtocolUnsupportedByAddressFamily,ProtocolUnsupportedBySystem,SocketModeUnsupported,SystemFdQuotaExceeded,SystemResources,Timeout,Unexpected,UnsupportedClock,WouldBlock}!Io.net.Stream'
lib/std/Io/net.zig:1195:20: note: struct declared here
pub const Stream = struct {
                   ^~~~~~
lib/std/Io.zig:2049:76: note: function return type declared here
        pub fn getOne(q: *@This(), io: Io) (QueueClosedError || Cancelable)!Elem {
                                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
referenced by:
    connect: lib/std/Io/net/HostName.zig:232:37
    connectTcpOptions: lib/std/http/Client.zig:1446:34
    12 reference(s) hidden; use '-freference-trace=14' to see all references
lib/std/Io.zig:2061:23: error: expected type 'error{Closed}!T', found 'T'
            return buf[0];
                   ~~~^~~
lib/std/Io.zig:2061:23: note: T = error{AccessDenied,AddressFamilyUnsupported,AddressUnavailable,Canceled,ConnectionPending,ConnectionRefused,ConnectionResetByPeer,HostUnreachable,NetworkDown,NetworkUnreachable,OptionUnsupported,ProcessFdQuotaExceeded,ProtocolUnsupportedByAddressFamily,ProtocolUnsupportedBySystem,SocketModeUnsupported,SystemFdQuotaExceeded,SystemResources,Timeout,Unexpected,UnsupportedClock,WouldBlock}!Io.net.Stream
lib/std/Io.zig:2061:23: note: error union payload 'Io.net.Stream' cannot cast into error union payload 'error{AccessDenied,AddressFamilyUnsupported,AddressUnavailable,Canceled,ConnectionPending,ConnectionRefused,ConnectionResetByPeer,HostUnreachable,NetworkDown,NetworkUnreachable,OptionUnsupported,ProcessFdQuotaExceeded,ProtocolUnsupportedByAddressFamily,ProtocolUnsupportedBySystem,SocketModeUnsupported,SystemFdQuotaExceeded,SystemResources,Timeout,Unexpected,UnsupportedClock,WouldBlock}!Io.net.Stream'
lib/std/Io/net.zig:1195:20: note: struct declared here
pub const Stream = struct {
                   ^~~~~~
lib/std/Io.zig:2058:72: note: function return type declared here
        pub fn getOneUncancelable(q: *@This(), io: Io) QueueClosedError!Elem {
                                                       ~~~~~~~~~~~~~~~~^~~~~
src/Compilation.zig:4864:1: error: emit MIR failed: InvalidInstruction (Zig compiler bug)
fn dispatchPrelinkWork(comp: *Compilation, main_progress_node: std.Progress.Node) void {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: error(x86_64_encoder): no encoding found for: none mov m256 imm8s none none
       
error: 3 compilation errors

Is that something that I have done wrong on my side?

[mathk]

Oddly when using llvm build it does work. Is that something missing in bootstrap build?

[lalinsky]

Interesting, it’s hitting this problem I found earlier.

Nested error union

I have a strange need for function that returns Cancelable!T, where T could also be an error union. Even though the compiler recognizes the nested error union, I can’t return the T value. src/select.zig:203:29: error: expected type 'error{Canceled}!error{Foo}!i32', found 'error{Foo}!i32' return fut.getResult(); ~~~~~~~~~~~~~^~ src/select.zig:203:29: note: error union payload 'i32' cannot cast into error union payload 'error{Foo}!i32' src/select.zig:186:54: note: function …

Apparently something in the Zig standard library wanted to use std.Io.Queue on elements that are error unions, from a function that also wants to return its own error set, but the compiler doesn’t like it.

Either std or the compiler needs to be fixed.