diff --git a/include/spho/ctx.h b/include/spho/ctx.h
index 746126c..fbc27e5 100644
--- a/include/spho/ctx.h
+++ b/include/spho/ctx.h
@@ -3,6 +3,9 @@
 
 #include "spho/data.h"
 
+#define SPHO_ERR_BUF_LEN	2048
+#define SPHO_ERR_FILEBUF_LEN	128
+
 struct spho_ctx {
 	int	err;
 	int	err_info;
@@ -20,6 +23,6 @@ struct spho_ctx {
 
 struct spho_ctx		*spho_ctx_create(void);
 void			spho_ctx_destroy(struct spho_ctx *);
-char			*spho_ctx_strerror(struct spho_ctx *);
+const char		*spho_ctx_strerror(struct spho_ctx *);
 
 #endif
diff --git a/include/spho/data.h b/include/spho/data.h
index 2050387..837f273 100644
--- a/include/spho/data.h
+++ b/include/spho/data.h
@@ -24,13 +24,13 @@ struct spho_nom_le {
 	SLIST_ENTRY(spho_nom_le)	next;
 };
 
-struct spho_const_le {
+struct spho_cnst_le {
 	struct spho_cnst		cnst;
-	SLIST_ENTRY(spho_const_le)	next;
+	SLIST_ENTRY(spho_cnst_le)	next;
 };
 
 
 SLIST_HEAD(spho_nom_l, spho_nom_le);
-SLIST_HEAD(spho_const_l, spho_const_le);
+SLIST_HEAD(spho_const_l, spho_cnst_le);
 
 #endif
diff --git a/include/spho/err.h b/include/spho/err.h
index f92687a..b11db1b 100644
--- a/include/spho/err.h
+++ b/include/spho/err.h
@@ -16,6 +16,7 @@
 			ctx->err_info = errno;				\
 		snprintf(ctx->filebuf, sizeof(ctx->filebuf), "%s",	\
 		    __FILE__);						\
+		ctx->filebuf[sizeof(ctx->filebuf) - 1] = '\0';		\
 		ctx->errline = __LINE__;				\
 	} while (0)
 
diff --git a/include/spho/spho.h b/include/spho/spho.h
index 900444f..780e5d7 100644
--- a/include/spho/spho.h
+++ b/include/spho/spho.h
@@ -7,26 +7,4 @@
 
 #include "spho/data.h"
 
-#define SPHO_ERR_BUF_LEN	2048
-#define SPHO_ERR_FILEBUF_LEN	128
-
-struct spho_ctx {
-	int	err;
-	int	err_info;
-
-	struct spho_nom_l	noms;
-	struct spho_const_l	cnsts;
-
-#ifdef SPHO_DEBUG
-	char filebuf[SPHO_ERR_FILEBUF_LEN];
-	int errline;
-#else
-	char errbuf[SPHO_ERR_BUF_LEN];
-#endif
-};
-
-struct spho_ctx		*spho_ctx_create(void);
-void			spho_ctx_destroy(struct spho_ctx *);
-char			*spho_ctx_strerror(struct spho_ctx *);
-
 #endif
diff --git a/src/run/devcheck.c b/src/run/devcheck.c
index e69de29..9a59086 100644
--- a/src/run/devcheck.c
+++ b/src/run/devcheck.c
@@ -0,0 +1,6 @@
+
+
+int main(void)
+{
+	return (0);
+}
diff --git a/src/spho/ctx.c b/src/spho/ctx.c
index 938863f..e1a39c3 100644
--- a/src/spho/ctx.c
+++ b/src/spho/ctx.c
@@ -1,15 +1,18 @@
+#include <sys/queue.h>
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
+#include "spho/err.h"
 #include "spho/ctx.h"
 
 static const char *spho_ctx_sys_strerror(struct spho_ctx *);
 static const char *spho_ctx_intern_strerror(struct spho_ctx *);
 
 struct spho_err {
-	int	num;
-	char	*msg;
+	int		err;
+	const char	*msg;
 };
 
 struct spho_err spho_errmsgs[] = {
@@ -43,15 +46,15 @@ spho_ctx_destroy(struct spho_ctx *ctx)
 
 	SPHO_PRECOND(ctx != NULL);
 
-	while (! SLIST_EMPTY(&c->noms)) {
-		nom = SLIST_FIRST(&c->noms);
-		SLIST_REMOVE_HEAD(&c->noms, next);
+	while (! SLIST_EMPTY(&ctx->noms)) {
+		nom = SLIST_FIRST(&ctx->noms);
+		SLIST_REMOVE_HEAD(&ctx->noms, next);
 		free(nom);
 	}
 
-	while (! SLIST_EMPTY(&c->cnsts)) {
-		cnst = SLIST_FIRST(&c->cnsts);
-		SLIST_REMOVE_HEAD(&c->cnsts, next);
+	while (! SLIST_EMPTY(&ctx->cnsts)) {
+		cnst = SLIST_FIRST(&ctx->cnsts);
+		SLIST_REMOVE_HEAD(&ctx->cnsts, next);
 		free(cnst);
 	}
 }
@@ -60,8 +63,8 @@ spho_ctx_destroy(struct spho_ctx *ctx)
 const char *
 spho_ctx_strerror(struct spho_ctx *ctx)
 {
-	char *msg;
 	int res;
+	const char *msg;
 
 	SPHO_PRECOND(ctx != NULL);
 
@@ -81,6 +84,10 @@ spho_ctx_strerror(struct spho_ctx *ctx)
 static const char *
 spho_ctx_sys_strerror(struct spho_ctx *ctx)
 {
+	int res;
+
+	SPHO_POSTCOND(ctx != NULL);
+
 #ifdef SPHO_DEBUG
 	res = snprintf(ctx->errbuf, sizeof(ctx->errbuf),
 	    "%s:%d:spho_syserr:%s (%d)", ctx->filebuf, ctx->errline,
@@ -89,8 +96,8 @@ spho_ctx_sys_strerror(struct spho_ctx *ctx)
 		ctx->errbuf[sizeof(ctx->errbuf) - 1] = '\0';
 #else
 	res = snprintf(ctx->errbuf, sizeof(ctx->errbuf),
-	    "spho_syserr:%s (%d)", ctx->filebuf, ctx->errline,
-	    strerror(ctx->err_info), ctx->err_info);
+	    "spho_syserr:%s (%d)", strerror(ctx->err_info),
+	    ctx->err_info);
 	if (res >= sizeof(ctx->errbuf))
 		ctx->errbuf[sizeof(ctx->errbuf) - 1] = '\0';
 #endif