Fix some Linux-dependent code

Signed-off-by: yamacir-kit <[email protected]>

README.md

@@ -90,7 +90,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.229_amd64.deb
+sudo apt install build/meevax_0.5.230_amd64.deb
 ```
 
 or
@@ -122,9 +122,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.229.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.230.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.229_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.230_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage

VERSION

@@ -1 +1 @@
-0.5.229
+0.5.230

include/meevax/kernel/library.hpp

@@ -17,6 +17,8 @@
 #ifndef INCLUDED_MEEVAX_KERNEL_LIBRARY_HPP
 #define INCLUDED_MEEVAX_KERNEL_LIBRARY_HPP
 
+#include <map>
+
 #include <meevax/kernel/environment.hpp>
 #include <meevax/kernel/interaction_environment.hpp>
 
@@ -60,10 +62,6 @@ inline namespace kernel
 
   auto operator <<(std::ostream &, library const&) -> std::ostream &;
 
-  /*
-     In order to improve the usability of the help procedure, it is desirable
-     to sort by library name in lexicographical order.
-  */
   auto libraries() -> std::map<std::string, library> &;
 
   template <typename T, typename... Ts>

include/meevax/memory/allocator.hpp

@@ -32,7 +32,7 @@ inline namespace memory
 template <typename T, typename Capacity = std::integral_constant<std::size_t, 1024>>
 class allocator
 {
-  struct alignas(T) chunk
+  struct chunk
   {
     chunk * tail;
   };

src/kernel/boot.cpp

@@ -35,6 +35,8 @@
 #include <meevax/kernel/standard_output_port.hpp>
 #include <meevax/kernel/vector.hpp>
 
+extern char ** environ; // for procedure get-environment-variables
+
 namespace meevax
 {
 inline namespace kernel