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fix: use runtime dlvsym instead of link-time .symver for cfgetospeed compat
The .symver approach broke the final link (ncurses' own -Wl,--version-script conflicts with a link-time versioned external symbol reference), and separately, the naive dlvsym-with-fallback first attempt still linked a bare reference to cfgetospeed for its fallback path, which just re-added the GLIBC_2.42 requirement it was meant to avoid. Resolving both dlvsym and its dlsym fallback dynamically (never referencing the bare cfgetospeed identifier in compiled code) sidesteps the linker entirely and degrades gracefully on any glibc, verified by building the patched ncurses against the bumped glibc: no cfgetospeed reference of any kind remains in the dynamic symbol table, and the max GLIBC symbol requirement drops back to 2.38, matching every other library in the bundle.
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Lines changed: 128 additions & 56 deletions

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‎nix/overlays/default.nix‎

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@@ -19,7 +19,7 @@
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# Force the pre-2.42 glibc symbol version for cfgetospeed so the portable CLI bundle keeps working on older-glibc hosts.
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ncurses = prev.ncurses.overrideAttrs (old: {
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patches = (old.patches or [ ]) ++ [ ./patches/ncurses-cfgetospeed-old-glibc-symver.patch ];
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patches = (old.patches or [ ]) ++ [ ./patches/ncurses-cfgetospeed-old-glibc-compat.patch ];
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});
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cargo-pgrx = final.callPackage ../cargo-pgrx/default.nix {

‎nix/overlays/patches/ncurses-cfgetospeed-old-glibc-compat.patch‎

Lines changed: 127 additions & 0 deletions
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@@ -0,0 +1,127 @@
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--- a/ncurses/tinfo/lib_baudrate.c 2026-07-31 08:24:24
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+++ b/ncurses/tinfo/lib_baudrate.c 2026-07-31 12:03:39
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@@ -45,6 +45,39 @@
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#endif
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/*
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+ * On Linux/glibc, resolve cfgetospeed to the old (functionally identical)
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+ * GLIBC_2.17 symbol version at runtime, so binaries built against newer
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+ * glibc still run on hosts with older glibc that only export that version.
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+ * Done via dlvsym rather than a link-time .symver directive, since the
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+ * latter conflicts with ncurses' own --version-script linking. Both dlvsym
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+ * and its dlsym fallback are declared directly (rather than via
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+ * <dlfcn.h>/_GNU_SOURCE, which may already be locked in by earlier headers
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+ * in this file), and neither path calls the bare cfgetospeed identifier, so
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+ * no versioned reference to it survives in the compiled output.
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+ */
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+#if defined(__linux__) && defined(__GLIBC__)
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+extern void *dlvsym(void *handle, const char *symbol, const char *version);
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+extern void *dlsym(void *handle, const char *symbol);
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+static speed_t
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+_supabase_compat_cfgetospeed(const struct termios *t)
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+{
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+ static int inited = 0;
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+ static speed_t (*fn)(const struct termios *) = NULL;
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+ if (!inited) {
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+ fn = (speed_t (*)(const struct termios *))
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+ dlvsym((void *) 0, "cfgetospeed", "GLIBC_2.17");
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+ if (!fn) {
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+ fn = (speed_t (*)(const struct termios *))
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+ dlsym((void *) 0, "cfgetospeed");
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+ }
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+ inited = 1;
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+ }
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+ return fn ? fn(t) : 0;
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+}
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+#define cfgetospeed(t) _supabase_compat_cfgetospeed(t)
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+#endif
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+
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+/*
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* These systems use similar header files, which define B1200 as 1200, etc.,
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* but can be overridden by defining USE_OLD_TTY so B1200 is 9, which makes all
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* of the indices up to B115200 fit nicely in a 'short', allowing us to retain
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--- a/ncurses/tinfo/tinfo_driver.c 2026-07-31 08:24:24
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+++ b/ncurses/tinfo/tinfo_driver.c 2026-07-31 12:03:50
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@@ -37,6 +37,39 @@
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#include <tic.h>
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#include <termcap.h> /* ospeed */
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+/*
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+ * On Linux/glibc, resolve cfgetospeed to the old (functionally identical)
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+ * GLIBC_2.17 symbol version at runtime, so binaries built against newer
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+ * glibc still run on hosts with older glibc that only export that version.
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+ * Done via dlvsym rather than a link-time .symver directive, since the
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+ * latter conflicts with ncurses' own --version-script linking. Both dlvsym
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+ * and its dlsym fallback are declared directly (rather than via
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+ * <dlfcn.h>/_GNU_SOURCE, which may already be locked in by earlier headers
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+ * in this file), and neither path calls the bare cfgetospeed identifier, so
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+ * no versioned reference to it survives in the compiled output.
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+ */
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+#if defined(__linux__) && defined(__GLIBC__)
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+extern void *dlvsym(void *handle, const char *symbol, const char *version);
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+extern void *dlsym(void *handle, const char *symbol);
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+static speed_t
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+_supabase_compat_cfgetospeed(const struct termios *t)
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+{
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+ static int inited = 0;
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+ static speed_t (*fn)(const struct termios *) = NULL;
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+ if (!inited) {
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+ fn = (speed_t (*)(const struct termios *))
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+ dlvsym((void *) 0, "cfgetospeed", "GLIBC_2.17");
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+ if (!fn) {
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+ fn = (speed_t (*)(const struct termios *))
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+ dlsym((void *) 0, "cfgetospeed");
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+ }
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+ inited = 1;
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+ }
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+ return fn ? fn(t) : 0;
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+}
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+#define cfgetospeed(t) _supabase_compat_cfgetospeed(t)
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+#endif
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+
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#if HAVE_NANOSLEEP
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#include <time.h>
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#if HAVE_SYS_TIME_H
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--- a/progs/tset.c 2026-07-31 08:24:24
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+++ b/progs/tset.c 2026-07-31 12:03:59
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@@ -89,6 +89,40 @@
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#include <reset_cmd.h>
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#include <termcap.h>
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#include <transform.h>
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+
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+/*
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+ * On Linux/glibc, resolve cfgetospeed to the old (functionally identical)
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+ * GLIBC_2.17 symbol version at runtime, so binaries built against newer
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+ * glibc still run on hosts with older glibc that only export that version.
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+ * Done via dlvsym rather than a link-time .symver directive, since the
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+ * latter conflicts with ncurses' own --version-script linking. Both dlvsym
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+ * and its dlsym fallback are declared directly (rather than via
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+ * <dlfcn.h>/_GNU_SOURCE, which may already be locked in by earlier headers
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+ * in this file), and neither path calls the bare cfgetospeed identifier, so
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+ * no versioned reference to it survives in the compiled output.
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+ */
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+#if defined(__linux__) && defined(__GLIBC__)
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+extern void *dlvsym(void *handle, const char *symbol, const char *version);
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+extern void *dlsym(void *handle, const char *symbol);
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+static speed_t
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+_supabase_compat_cfgetospeed(const struct termios *t)
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+{
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+ static int inited = 0;
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+ static speed_t (*fn)(const struct termios *) = NULL;
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+ if (!inited) {
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+ fn = (speed_t (*)(const struct termios *))
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+ dlvsym((void *) 0, "cfgetospeed", "GLIBC_2.17");
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+ if (!fn) {
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+ fn = (speed_t (*)(const struct termios *))
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+ dlsym((void *) 0, "cfgetospeed");
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+ }
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+ inited = 1;
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+ }
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+ return fn ? fn(t) : 0;
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+}
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+#define cfgetospeed(t) _supabase_compat_cfgetospeed(t)
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+#endif
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+
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#include <tty_settings.h>
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#if HAVE_GETTTYNAM

‎nix/overlays/patches/ncurses-cfgetospeed-old-glibc-symver.patch‎

Lines changed: 0 additions & 55 deletions
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