fairseq2n is not compatible with fmt in PyTorch nightlies about fairseq2

[cbalioglu]

Hey @ezyang, nice to see you here :) It has been a while. Sorry, we have been very busy lately, just catching up with some of the pending PRs. I checked #152 as well and looks like the ordering of the header file directories in compile commands causes the issue (we use a different version of fmt in fairseq2n). Just changed the reordering of CMake dependencies. Do you mind checking whether that works

[ezyang]

Here is a better workaround:

diff --git a/fairseq2n/src/fairseq2n/data/immutable_string.h b/fairseq2n/src/fairseq2n/data/immutable_string.h
index 86ba7bf..2e9817b 100644
--- a/fairseq2n/src/fairseq2n/data/immutable_string.h
+++ b/fairseq2n/src/fairseq2n/data/immutable_string.h
@@ -211,6 +211,10 @@ public:
    ~invalid_utf8_error() override;
 };
 
+inline auto format_as(const immutable_string& s) {
+  return s.to_string();
+}
+
 }  // namespace fairseq2n
 
 template <>
diff --git a/fairseq2n/src/fairseq2n/fmt.h b/fairseq2n/src/fairseq2n/fmt.h
index 44bc000..50e047e 100644
--- a/fairseq2n/src/fairseq2n/fmt.h
+++ b/fairseq2n/src/fairseq2n/fmt.h
@@ -20,6 +20,7 @@ struct repr {};  // disabled (i.e. poisoned)
 #include <string>
 #include <type_traits>
 
+#define FMT_HEADER_ONLY
 #include <fmt/core.h>
 #include <fmt/format.h>
 

[cbalioglu]

Closing for now. Feel free to reopen it if the issue persists.