Build of udpxy with musl toolchain

# [tuscan]
# Server = file:///var/cache/pacman/pkg/

# :: Synchronizing package databases...
# downloading tuscan.db...

# /sysroot/lib
# /sysroot/share
# /sysroot/bin
# /sysroot/include
# /sysroot/libexec

# ==> Making package: udpxy 1.0.23.9-1 (Wed Apr 5 00:20:39 UTC 2017)
# ==> Checking runtime dependencies...
# ==> Checking buildtime dependencies...
# ==> WARNING: Using existing $srcdir/ tree
# ==> Starting build()...
# gcc -O2 -DUDPXREC_MOD -MM udpxy.c sloop.c rparse.c util.c prbuf.c ifaddr.c ctx.c mkpg.c rtp.c uopt.c dpkt.c netop.c extrn.c main.c udpxrec.c > udpxy.dep
#
# Making a [release] version (use 'debug' target as an alternative)
#
# make[1]: Entering directory '/tmp/udpxy/src/udpxy-1.0.23-9'
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c udpxy.c -o udpxy.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c sloop.c -o sloop.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c rparse.c -o rparse.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c util.c -o util.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c prbuf.c -o prbuf.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c ifaddr.c -o ifaddr.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c ctx.c -o ctx.o
# ifaddr.c:150:33: warning: comparison of distinct pointer types ('char *' and 'void *') [-Wcompare-distinct-pointer-types]
# for( rec = ifc.ifc_buf; rec < (ifc.ifc_buf + ifc.ifc_len); ) {
# ~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c mkpg.c -o mkpg.o
# 1 warning generated.
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c rtp.c -o rtp.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c uopt.c -o uopt.o
# mkpg.c:93:29: warning: address of array 'client->tail' will always evaluate to 'true' [-Wpointer-bool-conversion]
# client->tail ? client->tail : "",
# ~~~~~~~~^~~~ ~
# mkpg.c:100:25: warning: address of array 'client->tail' will always evaluate to 'true' [-Wpointer-bool-conversion]
# if (client->tail && strlen(client->tail) > max_cli_tail)
# ~~~~~~~~^~~~ ~~
# 2 warnings generated.
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c dpkt.c -o dpkt.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c netop.c -o netop.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c extrn.c -o extrn.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c main.c -o main.o
# gcc -O2 -DUDPXREC_MOD -DNDEBUG -DTRACE_MODULE -c udpxrec.c -o udpxrec.o
# gcc -O2 -DNDEBUG -DTRACE_MODULE -o udpxy udpxy.o sloop.o rparse.o util.o prbuf.o ifaddr.o ctx.o mkpg.o rtp.o uopt.o dpkt.o netop.o extrn.o main.o udpxrec.o
# -rwxr-xr-x 1 tuscan tuscan 78616 Apr 5 00:20 udpxy
# ln -s udpxy udpxrec
# make[1]: Leaving directory '/tmp/udpxy/src/udpxy-1.0.23-9'
# ==> Entering fakeroot environment...
# ==> Starting package()...
# -rwxr-xr-x 1 tuscan tuscan 78616 Apr 5 00:20 /tmp/udpxy/pkg/udpxy/usr/bin/udpxy
# -rwxr-xr-x 1 tuscan tuscan 78616 Apr 5 00:20 /tmp/udpxy/pkg/udpxy/usr/bin/udpxrec
# Installation of udpxy is complete
# ==> Tidying install...
# -> Removing doc files...
# -> Purging unwanted files...
# ==> Checking for packaging issue...
# ==> Creating package "udpxy"...
# -> Generating .PKGINFO file...
# -> Generating .BUILDINFO file...
# error: invalid option '--noprogressbar'
# -> Generating .MTREE file...
# -> Compressing package...
# ==> Leaving fakeroot environment.
# ==> Finished making: udpxy 1.0.23.9-1 (Wed Apr 5 00:20:44 UTC 2017)

# udpxy 1.0.23.9-1

# udpxy 1.0.23.9-1

# /.PKGINFO
# /.MTREE
# /usr/bin/udpxy
# /usr/bin/udpxrec
# /usr/share/man/man1/udpxrec.1.gz
# /usr/share/man/man1/udpxy.1.gz
# /usr/lib/systemd/system/udpxy.service
# /sysroot/usr/lib/systemd/system/udpxy.service

# .PKGINFO

# ==> Extracting database to a temporary location...
# ==> Extracting database to a temporary location...
# ==> Adding package '/var/cache/pacman/pkg/udpxy.pkg.tar.xz'
# -> Computing checksums...
# -> Creating 'desc' db entry...
# -> Creating 'files' db entry...
# ==> Creating updated database file '/var/cache/pacman/pkg/tuscan.db.tar'