Merge pull request #14587 from NixOS/fix-mingw

treewide: Fix MinGW build

src/libutil/include/nix/util/terminal.hh

@@ -4,7 +4,15 @@
 #include <limits>
 #include <string>
 
+#include "nix/util/file-descriptor.hh"
+
 namespace nix {
+
+/**
+ * Determine whether \param fd is a terminal.
+ */
+bool isTTY(Descriptor fd);
+
 /**
  * Determine whether ANSI escape sequences are appropriate for the
  * present output.

src/libutil/terminal.cc

@@ -64,6 +64,16 @@ inline std::pair<int, size_t> charWidthUTF8Helper(std::string_view s)
 
 namespace nix {
 
+bool isTTY(Descriptor fd)
+{
+#ifndef _WIN32
+    return isatty(fd);
+#else
+    DWORD mode;
+    return GetConsoleMode(fd, &mode);
+#endif
+}
+
 bool isTTY()
 {
     static const bool tty = isatty(STDERR_FILENO) && getEnv("TERM").value_or("dumb") != "dumb"