@JesusChapman

/bin/sh: 1: /data/data/com.termux/files/usr/bin/protoc: Exec format error

Basically, unless I am also incorrect this time, unfortunately there is no such thing currently as termux_setup_protoc_cross_pkg_config_wrapper for softwares which are "trying to run" $PREFIX/bin/protoc during cross-compilation.

Therefore, this time it really is necessary to apply a patch and/or other kind of termux_step_pre_configure() build.sh workaround for protoc, to make it use termux_setup_protobuf followed by export PROTOC=$(command -v protoc) OR other kind of directive to the build system of the software (varies between different softwares) instead of there being a single universal uniformly applicable workaround.

SOME currently preexisting examples:

in this case, it can be observed that the bear software is using find_program() in CMake to try to detect the protoc executable.

This means that its CMake log is going to contain this:

-- Looking for protoc ... /data/data/com.termux/files/usr/bin/protoc

until you get it to successfully change to a different protoc that is executable during cross-compilation.

Additionally, once you resolve that problem, you would next encounter another error, like this:

/data/data/com.termux/files/usr/bin/grpc_cpp_plugin: program not found or is not executable

because, the bear software not only requires protoc at build-time, but also requires another program, grpc_cpp_plugin. Because of that, it's also necessary to set up a host grpc_cpp_plugin executable for cross-compiling and apply a similar CMake workaround patch to bear for it.

I have made an example of doing these steps successfully for you, here it is:

packages/bear/build.sh

TERMUX_PKG_HOMEPAGE=https://github.com/rizsotto/Bear
TERMUX_PKG_DESCRIPTION="Bear is a tool that generates a compilation database for clang tooling."
TERMUX_PKG_LICENSE="GPL-3.0"
TERMUX_PKG_MAINTAINER="@JesusChapman <jesuschapmandev@outlook.com>"
TERMUX_PKG_VERSION=3.1.6
TERMUX_PKG_SRCURL=https://github.com/rizsotto/Bear/archive/refs/tags/${TERMUX_PKG_VERSION}.zip
TERMUX_PKG_SHA256=efadb159f0d8ebab529ced6ba9f78d23754fbc1e484d169e6d92a88f92f44279
TERMUX_PKG_DEPENDS="libgrpc, fmt, libspdlog, jsoncpp, libandroid-spawn"
TERMUX_PKG_HOSTBUILD=true
TERMUX_PKG_EXTRA_CONFIGURE_ARGS="
-DENABLE_UNIT_TESTS=OFF
-DENABLE_FUNC_TESTS=OFF
"

termux_step_host_build() {
	if [ "$TERMUX_ON_DEVICE_BUILD" = "true" ]; then
		return
	fi

	# build and install grpc_cpp_plugin binary for using during cross-compilation
	local _GRPC_VERSION=$(bash -c ". $TERMUX_SCRIPTDIR/packages/libgrpc/build.sh; echo \${TERMUX_PKG_VERSION#*:}")
	local _GRPC_SRCURL=https://github.com/grpc/grpc.git
	local _GRPC_SRCDIR=${TERMUX_PKG_TMPDIR}/grpc-${_GRPC_VERSION}

	git clone --recursive --branch "v$_GRPC_VERSION" "$_GRPC_SRCURL" "$_GRPC_SRCDIR"

	termux_setup_cmake
	termux_setup_ninja

	cmake -G Ninja "$_GRPC_SRCDIR"

	ninja grpc_cpp_plugin
	# grpc_cpp_plugin host binary is now directly in the root of $TERMUX_PKG_HOSTBUILD_DIR
}

_setup_grpc() {
	if [ "$TERMUX_ON_DEVICE_BUILD" = "false" ]; then
		export PATH="$TERMUX_PKG_HOSTBUILD_DIR:$PATH"
	fi
}

termux_step_pre_configure() {
	termux_setup_protobuf
	_setup_grpc
	export PROTOC_PATH="$(dirname $(command -v protoc))"
	export GRPC_CPP_PLUGIN_PATH="$(dirname $(command -v grpc_cpp_plugin))"
	export LDFLAGS+=" -landroid-spawn"
}

packages/bear/cmake-find_program-search-paths.patch

--- a/source/intercept/proto/CMakeLists.txt
+++ b/source/intercept/proto/CMakeLists.txt
@@ -1,6 +1,6 @@
-find_program(_PROTOBUF_PROTOC protoc HINTS ${gRPC_BINDIR})
+find_program(_PROTOBUF_PROTOC protoc PATHS ENV PROTOC_PATH NO_DEFAULT_PATH)
 message(STATUS "Looking for protoc ... ${_PROTOBUF_PROTOC}")
-find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin HINTS ${gRPC_BINDIR})
+find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin PATHS ENV GRPC_CPP_PLUGIN_PATH NO_DEFAULT_PATH)
 message(STATUS "Looking for grpc_cpp_plugin ... ${_GRPC_CPP_PLUGIN_EXECUTABLE}")
 
 get_filename_component(SUPERVISE_PROTO "supervise.proto" ABSOLUTE)
--- a/third_party/grpc/CMakeLists.txt
+++ b/third_party/grpc/CMakeLists.txt
@@ -5,7 +5,7 @@ if (gRPC_FOUND)
     message(STATUS "Looking for gRPC::grpc++ dependency -- found")
 
     message(STATUS "Looking for protoc")
-    find_program(PROTOC protoc)
+    find_program(PROTOC protoc PATHS ENV PROTOC_PATH NO_DEFAULT_PATH)
     if (PROTOC)
         message(STATUS "Looking for protoc -- found")
     else()
@@ -13,7 +13,7 @@ if (gRPC_FOUND)
     endif()
 
     message(STATUS "Looking for grpc_cpp_plugin")
-    find_program(GRPC_CPP_PLUGIN grpc_cpp_plugin)
+    find_program(GRPC_CPP_PLUGIN grpc_cpp_plugin PATHS ENV GRPC_CPP_PLUGIN_PATH NO_DEFAULT_PATH)
     if (GRPC_CPP_PLUGIN)
         message(STATUS "Looking for grpc_cpp_plugin -- found")
     else()

@JesusChapman and if my message is too long and confusing I am sorry, basically if you see this, the short explanation is I made a cross-compilable version for you and put the files in code blocks at the bottom of the message, but I did not force push them into your branch. If you would like me to, I can do that as well.

@JesusChapman and if my message is too long and confusing I am sorry, basically if you see this, the short explanation is I made a cross-compilable version for you and put the files in code blocks at the bottom of the message, but I did not force push them into your branch. If you would like me to, I can do that as well.

Don't worry, I have no problem, I was thinking of doing it later, I'm in the army and I've just walked a long distance 😂