btfs2: Re-enable CGO

Partially reverts commit 88facc1a95.

packages/btfs2/build.sh

@@ -4,6 +4,7 @@ TERMUX_PKG_LICENSE="Apache-2.0, MIT"
 TERMUX_PKG_LICENSE_FILE="LICENSE-APACHE, LICENSE-MIT"
 TERMUX_PKG_MAINTAINER="Simbad Marino <cctechmx@gmail.com>"
 TERMUX_PKG_VERSION=2.1.0
+TERMUX_PKG_REVISION=1
 TERMUX_PKG_SRCURL=https://github.com/bittorrent/go-btfs/archive/refs/tags/btfs-v${TERMUX_PKG_VERSION}.tar.gz
 TERMUX_PKG_SHA256=5960a0dbf57c7867cc76189b66a4867f7da899f222bd32c53d226f3090c600e5
 TERMUX_PKG_AUTO_UPDATE=true
@@ -12,7 +13,18 @@ TERMUX_PKG_BUILD_IN_SRC=true
 
 termux_step_pre_configure() {
 	termux_setup_golang
-	export CGO_ENABLED=0
+	go mod init || :
+	go mod tidy
+
+	# Please do not ever disable CGO:
+	# https://github.com/termux/termux-packages/issues/9094
+	local _GOPATH=$(go env GOPATH)
+	pushd $_GOPATH/pkg/mod/github.com/karalabe/usb@*
+	local target=hidapi/libusb/hid.c
+	chmod 0755 $(dirname $target)
+	chmod 0644 $target
+	patch -p1 < $TERMUX_PKG_BUILDER_DIR/karalabe-usb-pthread_barrier.patch.diff
+	popd
 }
 
 termux_step_make() {

packages/btfs2/karalabe-usb-pthread_barrier.patch.diff

@@ -0,0 +1,24 @@
+From e188e2d7eefa1a057a20921236f22a6008b29c93 Mon Sep 17 00:00:00 2001
+From: Fredrik Fornwall <fredrik@fornwall.net>
+Date: Thu, 12 Dec 2019 01:07:20 +0100
+Subject: [PATCH] Fix build when targetting Android 7 or later
+
+Support for pthread_barrier was introduced in Android 7, so trying to
+build a custom implementation of that clashes with the system headers.
+---
+ hidapi/libusb/hid.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/hidapi/libusb/hid.c b/hidapi/libusb/hid.c
+index 474dff4..dd6fd8c 100644
+--- a/hidapi/libusb/hid.c
++++ b/hidapi/libusb/hid.c
+@@ -49,7 +49,7 @@
+ 
+ #include "hidapi.h"
+ 
+-#ifdef __ANDROID__
++#if defined(__ANDROID__) && __ANDROID_API__ < __ANDROID_API_N__
+ 
+ /* Barrier implementation because Android/Bionic don't have pthread_barrier.
+    This implementation came from Brent Priddy and was posted on