When linking with library flags generated by pkg-config, the -ljpeg flag is duplicated

[georgestagg]

See discussion in #152 for more context. The short version is that duplicated link flags fails when building for webR/Wasm with Emscripten.

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In the package's configure script, pkg-config is used to find libjpeg,

ragg/configure

Line 8 in 792c1e1

PKG_CONFIG_NAME="freetype2 libpng libtiff-4 libjpeg"

but later, the -ljpeg flag is also manually appended,

ragg/configure

Lines 37 to 39 in 792c1e1

	echo "Found pkg-config cflags and libs!"
	PKG_CFLAGS=${PKGCONFIG_CFLAGS}
	PKG_LIBS="${PKGCONFIG_LIBS} -ljpeg"

If we are relying on pkg-config and the existence of jpeg.pc, can we remove the additional -ljpeg?

Alternatively, should fa87a16 be reverted? The argument for that is that older versions of libjpeg did not install a jpeg.pc for pkg-config to use.

I don't particularly mind which of the two solutions we land on.

[jeroen]

As I am listed as the official author of this particular script, I'll use my executive powers here :)

I checked a few old linux distros and all of them install the libjpeg-turbo drop-in replacement instead of the original libjpeg implementation when you install libjpeg-dev or libjpeg-devel . The libjpeg-turbo library has always included a proper libjpeg.pc, so therefore requiring this is probably fine these days (otherwise we would have heard about it by now).