./configure not picking up zlib via pkg-config

[AleksejK1]

export CC=musl-gcc CFLAGS="-Os" 
./configure --enable-static
<...>
Checking for clock_gettime() ... yes.
Checking for InflateInit2() ... Failed to link with your system's zlib, can't continue...
export PKG_CONFIG_PATH=/usr/lib/zlib-ng-compat-static/pkgconfig
./configure --enable-static
<...>
Checking for clock_gettime() ... yes.
Checking for InflateInit2() ... Failed to link with your system's zlib, can't continue...

But providing zlib headers/libz.a locations manually works:

export CC=musl-gcc CFLAGS="-I/usr/include/zlib-ng-compat-static -Os" LDFLAGS="-L/usr/lib/zlib-ng-compat-static -static"
./configure --enable-static
<...>
Checking for InflateInit2() ... yes.
Checking for pkg-config ... yes
Checking for libarchive >= 3.3.3  via pkg-config ... found version 3.8.1.
Checking for libssl via pkg-config ... found OpenSSL version 3.5.0.

PKG_CONFIG_PATH works for other libs (overriding OpenSSL with LibreSSL here):

export PKG_CONFIG_PATH=/usr/lib/libressl-static/pkgconfig
./configure --enable-static
Checking for InflateInit2() ... yes.
Checking for pkg-config ... yes
Checking for libarchive >= 3.3.3  via pkg-config ... found version 3.8.1.
Checking for libssl via pkg-config ... found LibreSSL version 4.1.0.

[AleksejK1]

Doesn't work, maybe because new check line 696 starts with "if false"? If I change line 696 to just "if pkg-config --exists 'zlib'; then" it works.

…

On 2025-07-30, Duncan Overbruck wrote: Closed #642 as completed via b1e8d01. -- Reply to this email directly or view it on GitHub: #642 (comment) You are receiving this because you authored the thread. Message ID: ***@***.***>

[Duncaen]

Right that was left over from testing the fallback.