Crystal i for linux

diff.diff

diff --git c/src/compiler/crystal/repl/context.cr w/src/compiler/crystal/repl/context.cr
index 1cceb2c45..3451a87d0 100644
--- c/src/compiler/crystal/repl/context.cr
+++ w/src/compiler/crystal/repl/context.cr
@@ -471,8 +472,14 @@ class Crystal::Repl::Context

     return unless path && name

-    # TODO: obviously support other platforms than darwin
-    lib_path = File.join(path, "lib#{name}.dylib")
+    lib_path : String?
+    {% if flag?(:darwin) %}
+      lib_path = File.join(path, "lib#{name}.dylib")
+    {% elsif flag?(:unix) %}
+      lib_path = File.join(path, "lib#{name}.so")
+    {% else %}
+      {% raise "Can't load dynamic libraries" %}
+    {% end %}
     return unless File.exists?(lib_path)

     handle = LibC.dlopen(lib_path, LibC::RTLD_LAZY | LibC::RTLD_GLOBAL)
diff --git c/src/crystal/system/unix/file_descriptor.cr w/src/crystal/system/unix/file_descriptor.cr
index bc3576a2f..2000fed13 100644
--- c/src/crystal/system/unix/file_descriptor.cr
+++ w/src/crystal/system/unix/file_descriptor.cr
@@ -64,11 +64,19 @@ module Crystal::System::FileDescriptor
   end

   private def system_info
-    if LibC.fstat(fd, out stat) != 0
-      raise IO::Error.from_errno("Unable to get info")
-    end
+    {% begin %}
+      {% if flag?(:interpreted) %}
+        ret = LibC.__fxstat(1, fd, out stat)
+      {% else %}
+        ret = LibC.fstat(fd, out stat)
+      {% end %}

-    FileInfo.new(stat)
+      if ret != 0
+        raise IO::Error.from_errno("Unable to get info")
+      end
+
+      FileInfo.new(stat)
+    {% end %}
   end

   private def system_seek(offset, whence : IO::Seek) : Nil
diff --git c/src/crystal/system/unix/pthread.cr w/src/crystal/system/unix/pthread.cr
index 4af585abe..15545912e 100644
--- c/src/crystal/system/unix/pthread.cr
+++ w/src/crystal/system/unix/pthread.cr
@@ -154,7 +154,7 @@ class Thread
       raise RuntimeError.from_os_error("pthread_attr_destroy", Errno.new(ret)) unless ret == 0
     {% elsif flag?(:linux) %}
       if LibC.pthread_getattr_np(@th, out attr) == 0
-        LibC.pthread_attr_getstack(pointerof(attr), pointerof(address), out _)
+        LibC.pthread_attr_getstack(pointerof(attr), pointerof(address), out x)
       end
       ret = LibC.pthread_attr_destroy(pointerof(attr))
       raise RuntimeError.from_os_error("pthread_attr_destroy", Errno.new(ret)) unless ret == 0
diff --git c/src/lib_c/x86_64-linux-gnu/c/sys/stat.cr w/src/lib_c/x86_64-linux-gnu/c/sys/stat.cr
index 46c5d472c..446efef3d 100644
--- c/src/lib_c/x86_64-linux-gnu/c/sys/stat.cr
+++ w/src/lib_c/x86_64-linux-gnu/c/sys/stat.cr
@@ -46,6 +46,7 @@ lib LibC

   fun chmod(file : Char*, mode : ModeT) : Int
   fun fstat(fd : Int, buf : Stat*) : Int
+  fun __fxstat(ver : Int, fd : Int, buf : Stat*) : Int
   fun lstat(file : Char*, buf : Stat*) : Int
   fun mkdir(path : Char*, mode : ModeT) : Int
   fun mkfifo(path : Char*, mode : ModeT) : Int