Building the mam.client.js (actually the iota-bindings)

Question

I am trying to build according to the instructions given:

https://github.com/iotaledger/mam.client.js

There are a whole lot of other steps then just described there which mainly relate to building everything rust & emscripten. As far I got I have everything setup correctly (I can build the normal iotaledger/MAM rust project) and everything however.. when I build the iota-bindings I get errors! Totally unfortunate and I am even developing on windows. The problem is I am totally lost and the error is to generic to make a good google search to figure out what is wrong especially since I never used rust or emscripten before so here is the error:

 [218] ./iota-bindings/emscripten/src/main.rs 17.6 kB {0} [built] [failed] [1 error]
 [219] ./src/index.js 18.8 kB {0} [built]
 [462] (webpack)/buildin/module.js 517 bytes {0} [built]
 [537] ./src/encryption.js 2.45 kB {0} [built]
    + 533 hidden modules

ERROR in ./iota-bindings/emscripten/src/main.rs
Module build failed: Error: Command failed: cargo build --target=wasm32-unknown-emscripten --release
    Updating git repository `https://github.com/japaric/cty.git`
    Updating git repository `https://github.com/iotaledger/iota.rs.git`
    Updating git repository `https://github.com/iotaledger/MAM.git`
    Updating git repository `https://github.com/iotaledger/iota-bindings.git`
   Compiling iota-trytes v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling cty v0.1.5 (https://github.com/japaric/cty.git#4d8b2525)
   Compiling iota-curl v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-tmath v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-pascal v0.1.0 (https://github.com/iotaledger/MAM.git#413f0479)
   Compiling iota-bindings-shared v0.1.0 (https://github.com/iotaledger/iota-bindings.git#c382969e)
   Compiling iota-bindings-shared v0.1.0 (file:///C:/altos_git/IOTA/mam.client.js/iota-bindings/shared)
   Compiling iota-kerl v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-curl-cpu v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-sign v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-models v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-merkle v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-mam v0.1.0 (https://github.com/iotaledger/MAM.git#413f0479)
   Compiling iota-bindings v0.1.0 (https://github.com/iotaledger/iota.rs.git#56205e66)
   Compiling iota-mam-bindings v0.1.0 (https://github.com/iotaledger/MAM.git#413f0479)
   Compiling iota-bindings-rlib v0.1.0 (file:///C:/altos_git/IOTA/mam.client.js/iota-bindings/rlib)
   Compiling iota-bindings-emscripten v0.1.0 (file:///C:/altos_git/IOTA/mam.client.js/iota-bindings/emscripten)
warning: crate `IOTA` should have a snake case name such as `iota`
  |
  = note: #[warn(non_snake_case)] on by default

warning: unused attribute
   --> src/main.rs:6:1
    |
6   | / #[link_args = "-s EXPORTED_FUNCTIONS=[\
7   | | '_iota_ctrits_convert',\
8   | | '_iota_ctrits_ctrits_byte_length',\
9   | | '_iota_ctrits_ctrits_data',\
...   |
116 | | '_iota_mam_parse'\
117 | | ]"]
    | |___^
    |
    = note: #[warn(unused_attributes)] on by default

error: linking with `emcc.bat` failed: exit code: 1
  |
  = note: "cmd" "/c" "emcc.bat" "-s" "DISABLE_EXCEPTION_CATCHING=0" "-L" "C:\\Users\\olaf\\.rustup\\toolchains\\nightly-x86_64-pc-windows-msvc\\lib\\rustlib\\wasm32-unknown-emscripten\\lib" "C:\\altos_git\\IOTA\\mam.client.js\\iota-bindings\\emscripten\\target\\wasm32-unknown-emscripten\\release\\deps\\IOTA.IOTA0-436aa6619a00d1c9daf597c710019f2e.rs.rcgu.o" "C:\\altos_git\\IOTA\\mam.client.js\\iota-bindings\\emscripten\\target\\wasm32-unknown-emscripten\\release\\deps\\IOTA.IOTA1-436aa6619a00d1c9daf597c710019f2e.rs.rcgu.o" "-o" "C:\\altos_git\\IOTA\\mam.client.js\\iota-bindings\\emscripten\\target\\wasm32-unknown-emscripten\\release\\deps\\IOTA.js" "-s" "EXPORTED_FUNCTIONS=[\"_main\",\"_iota_ctrits_convert\",\"_iota_ctrits_ctrits_from_bytes\",\"_iota_ctrits_ctrits_length\",\"_iota_ctrits_ctrit        ...........................k\',\'_iota_models_v2_tx_set_value\',\'_iota_models_v2_tx_signature_or_message\',\'_iota_models_v2_tx_tag\',\'_iota_models_v2_tx_timestamp\',\'_iota_models_v2_tx_trunk\',\'_iota_models_v2_tx_value\',\'_iota_sign_checksum\',\'_iota_sign_checksum_validate\',\'_iota_sign_iss_address\',\'_iota_sign_iss_digest_bundle_signature\',\'_iota_sign_iss_digest_key\',\'_iota_sign_iss_key\',\'_iota_sign_iss_signature\',\'_iota_sign_iss_subseed\',\'_iota_sign_iss_subseed_to_signature\',\'_iota_mam_create\',\'_iota_mam_parse\']" "-s" "BINARYEN=1" "-s" "ERROR_ON_UNDEFINED_SYMBOLS=1"
      = note: Traceback (most recent call last):
                File "C:\altos_git\emsdk\emscripten\1.37.15\\emcc", line 13, in <module>
                  emcc.run()
                File "C:\altos_git\emsdk\emscripten\1.37.15\emcc.py", line 880, in run
                  exec 'shared.Settings.' + key + ' = ' + value in globals(), locals()
                File "<string>", line 1, in <module>
              NameError: name '_main' is not defined


    error: aborting due to previous error

    error: Could not compile `iota-bindings-emscripten`.

    To learn more, run the command again with --verbose.

        at ChildProcess.exithandler (child_process.js:275:12)
        at emitTwo (events.js:126:13)
        at ChildProcess.emit (events.js:214:7)
        at maybeClose (internal/child_process.js:925:16)
        at Socket.stream.socket.on (internal/child_process.js:346:11)
        at emitOne (events.js:116:13)
        at Socket.emit (events.js:211:7)
        at Pipe._handle.close [as _onclose] (net.js:554:12)
     @ ./src/web.js 3:11-61

I hope someone can help me with this or at least give me a direction that doesn't include using another OS.

Greets